Alchemy is a concept that holds a large influence over the Golden Sun series as a whole, and is closely related to the realized concepts of the Elements and that which may be used to control elements, Psynergy. This subject is somewhat difficult to grasp and has some speculatory aspects to it because of how vaguely explained it is in the games and how stated information about it may be pieced together in different ways to allow for different conclusions to be drawn. The plot elements termed the Golden Sun and the Stone of Sages are closely related components of Alchemy, and are thus covered here in full detail (along with general descriptions of the collective Elemental Lighthouses and Elemental Stars) for the purposes of clarity. Felix and Isaac agree to light the remaining lighthouses after the Mercury and Venus lighthouses were lit, so as to bring the elements back into balance and avoid a catastrophe.
It is important to lay out how the named and known aspects of Alchemy and related concepts relate to each other in order to draw supported conclusions:
- The world of Weyard is comprised of the Greek concept of Classical Elements in that all matter on the world and its denizens are comprised of any combination of four base Elements: Venus (representing earth), Mars (representing fire), Jupiter (representing air), and Mercury (representing water). The concept of Psynergy revolves around an individual with spiritual power (an "Adept") being able to use their power to manipulate one specific element out of the four present in his or her environment, with that specific element matching up with whichever element the user is innately attuned to and can be counted as an Adept of (example: a Mercury Adept can use Mercury Psynergy to manipulate water and cold-based aspects).
- The official backstory of the GBA series is that ages ago, in the ancient past of Weyard, the power of Alchemy was available to the peoples of the world. This great power could achieve effects both wonderous and terrible; with it, one could perform a complete transfusion of matter so that mere lead could become gold, and even death itself could be thwarted. This was the driving catalyst behind the development of great civilizations and empires, but as it could be said to have been expected, people with dreams of power and dominion attempted to use Alchemy's power for developing militaries and waging wars in the name of conquest. The world would have been torn apart by war were it not for a few brave and wise men, who took it upon themselves to place Alchemy out of the reach of mankind via a seal, and thus Alchemy disappeared from Weyard.
- Alchemy and the variously named, related aspects discussed later in this article are heavily based on the real-world topic of Alchemy and its associated legends. For starters, the best-known goals of the alchemists of the real world were the transmutation of common metals into gold, which in concept would have meant restructuring the basic building blocks of the matter of the metal involved so that it could be reformed into the matter makeup of gold or another metal. It was reasoned that the rearrangement of a metal's basic qualities so that the transmutation of one metal into another could be achieved would presumably be mediated by an unknown, mystical substance called "elixir", which could be ground and created from a legendary, theoretical stone the alchemists perceived and labeled the Philosopher's stone or "stone of Sages". The "elixir" referred to was also often equated to be the "Elixir of Life", which would bestow immortality upon the one who drinks it. Plot elements present in Golden Sun games are call-outs to these rather mythical concepts once held by researchers of the real world, such as the Lemurian draught, whose connection with the Golden Sun version of Alchemy causes those who drink it to have their life extended, which sounds like the Elixir of life. The Stone of Sages is the in-game spiritual equivalent to the Philosopher's Stone and its fabled properties of turning any metal into gold and producing the Elixir of life.
From the above three main points, the following statements about what is Alchemy in the Golden Sun series can be reasonably concluded: Alchemy is the concept of manipulating all four elements together at once, just as Psynergy is the concept of manipulating one and only one element at a time. Since Alchemy can turn one substance into another, it would have to do so by taking control of and manipulating the base building blocks that comprise the matter involved, and since all substances in Weyard are comprised of four Elements, each of which are normally individually manipulated by Psynergy, Alchemy has to be at least equivalent to the concept of the usage of a combined, unified form of the four elemental schools of Psynergy simultaneously in order for it to achieve the games' reported concept of transfusing substances into other substances entirely.
There are four great towers situated across Weyard named the Elemental Lighthouses, each one representing one of the four Elements, and each one of them may have lit upon its aerie a great, swirling sphere of energy referred to as that Lighthouse's Beacon. Each elemental Beacon, while active, exudes an unseen influence based on its respective element upon the world at large. In Golden Sun, a mural on a wall in the lower portion of Venus Lighthouse seems to give a clue about the origins of the Lighthouses; they were constructed by mankind, and they used Psynergy to do it. In-game dialogue from The Lost Age claims that at the time in the ancient past when the wars were being fought, when Alchemy was sealed away, the four elemental beacons were put out, which was a contributing factor as to how people lost the capacity to wage large-scale wars after the event.
There are four spherical jewels known as the Elemental Stars, each of which contains the purified essence of its respective element. Apparently these contained essences are the Beacons of the Lighthouses, because when an Elemental Star is cast down the well of the Elemental Lighthouse of the matching element, the elemental essence within the Star is extracted and channeled by the Lighthouse via the structure's internal mechanics, and the essence assumes the form of a large, swirling sphere of energy just above the Lighthouse's aerie to become that Lighthouse's Elemental Beacon once again. While it is not stated within the games, taking this information together with what is known about how the Elemental Beacons were alight originally but then put out in the ancient past can lead to the hypothesis that the Elemental Stars were apparently originally empty jewels that were used to suck each Lighthouse Beacon into themselves, so that the Beacons could be contained and taken away but be allowed to be restored to their former splendor at a later date.
Incidentally, the world of Weyard can be thought of in some ways as a living being which needs some form of sustenance to survive. The four Beacons and the unseen elemental energy they generate to reach across the entire world - when balanced out with all four elements - serve as the nourishment the world needs. When the Lighthouse Beacons were gone, from then on the world was cut off from its "food source", and as a result has gradually physically waned and shrunk over time; the original supercontinent of the world broke up into smaller continents that themselves shrank in size, and Gaia Falls - the name used to collectively refer to the perpetual waterfalls into the abyss comprising the entire world's perimeter - has been gradually consuming the world's perimeter and moving further inward, decreasing Weyard in diameter. Restoring the Lighthouse Beacons with the Elemental Stars is therefore what is necessary to prevent the world from buckling in and degenerating into nothingness in the future (and though this is speculation, it is possible that the system of Alchemy's seal was specifically designed so that the four Lighthouse Beacons could be returned ages down the line so as to stave off the otherwise inevitable end-of-the-world scenario of the future). All four Beacons would have to be lit for Weyard to be in the necessary state of equilibrium, though; calamities would occur if some but not all of the Beacons are alight. For example, at the start of The Lost Age, the combined influence of the Mercury and Venus beacons are what cause the monster Poseidon to awaken from his slumber and start causing trouble. Late in the game, when the Jupiter Beacon is lit as well, the combined influence of the three beacons suddenly causes the entire world to get gradually colder, because the element of the last Beacon, Mars, is the element of fire and warmth, and the global influence of warmth the Mars Beacon would provide is absent while the other three are in force. If the Mars Beacon is not lit in time in this case, Weyard would eventually be plunged into ice. (All of the above constitutes why it is always said that bringing back Alchemy would save Weyard from collapse/being frozen; as a matter of fact, it's not the power of Alchemy itself that sustains the world, it's the four Lighthouse Beacons, which happen to also bring back the power of Alchemy once they are simultaneously alight.)Geographically, in the region of Weyard that lies at the central point between where the four Lighthouses are situated is a mountain named Mt. Aleph, which legends claim has stood "since the world began". It would be an active volcano were it not for the fact that constructed within its interior is a shrine known as Sol Sanctum, and within the deepest part of the sanctum, in an area referred to as the Elemental Star Chamber, the four Elemental Stars were sealed onto pedestals in a way that would let their combined power suppress the magma underground below, and keep Mt. Aleph dormant for ages to come.
Even knowing all of the above, it still is something of a mystery as to how exactly Alchemy itself was sealed and made to disappear from the world of Weyard, in particular to what degree removing the four Elemental Beacons from their Lighthouse aeries contributed. What is verifiable, however, is that the Lighthouses are constructed and arranged, working along with Mt. Aleph itself, as the system which may bring the concept of Alchemy back to the world of Weyard and its people.
Should all four Elemental Lighthouses have their Lighthouse Beacons be alight simultaneously, the four structures will somehow detect this fact, and they are "pre-programmed" to react accordingly once they do; the four beacons will then simultaneously shoot out beams of their respective elemental energy into the same point of airspace above Mt. Aleph, and the beams make contact with each other and merge to form a golden pillar of energy that immediately bathes the peak of Mt. Aleph below. This is the "Golden Sun", which is described at the end of The Lost Age as "pure Alchemy made real, at the heart of its power" because it is the combination of all four elemental essences into a blended whole, which "gives shape to the Stone of Sages". This can be construed to mean that the merged power of the four elemental beams - i.e., the power of the Golden Sun - is being infused into Mt. Aleph below, apparently turning it into an object of immense Alchemic power. Radical as it may sound, it would be logical to conclude that the distinctively-appearing Mt. Aleph is in fact the Stone of Sages itself, and when imbued with the Golden Sun it becomes the physical commodity (easily recognizable as the glowing gold rock formation seen in the epilogue of The Lost Age) that provides the controllable concept of the power of Alchemy to the peoples of the world.
The plot progression of the GBA Golden Sun games revolves around two opposing groups, one attempting to use the Elemental Stars to light the Elemental Lighthouses so as to restore the force of Alchemy to the world of Weyard, the other a pursuing group set to stop them before the Elemental Lighthouses are lit. The first group raid Sol Sanctum and have the Elemental Stars removed from their pedestals (releasing the mystic bonds the Stars had in place so that the volcano's magma flows freely once again) and they set out on a global race to light each of the Elemental Lighthouses. The pursuing group is led by Isaac, who was tasked by the Wise One, the seemingly omniscient guardian of the seal placed on Alchemy, to prevent the other group as led by Saturos and Menardi from unleashing Alchemy unto the world, for as the Wise One claims, Alchemy is a power that could be dangerous if misused, and so it should be kept sealed as is. The Wise One clearly knows, however, how the process that returns Alchemy to the world - the lighting of the Elemental Lighthouses - is needed for the world to avert eventual self-destruction, but he also knows that it would be inevitable and frankly quick-to-occur for an attempt at dominion over the world to be made by means of Alchemy's powers. In not telling Isaac about this detail, the Wise One sets up a subtle test of Isaac's character and that of his party, relying on him to figure out and accept the truth of Alchemy's nature on his own at some point in his quest.
By the end of The Lost Age, when three Lighthouses have been lit, Isaac has learned the truth about Alchemy from remaining members of the party he was pursuing, and has thus made the decision to join forces with them to light Mars Lighthouse and save the world from being frozen by the lack of the Mars-based influence the Mars Beacon would provide. After much drama transpires on the aerie of Mars Lighthouse, the Mars Beacon is ultimately lit and equilibrium is restored to the world, and in the Wise One's eye, Isaac and his friends have risen to the Wise One's challenge and demonstrated their ability to make tough choices for the greater good of the world - the sort of virtue necessary to combat the likely tide of evil aspirations that may arise with Alchemy's restored presence on the world. The mechanisms described above play out; the Lighthouse Beacons simultaneously shoot their beams into the airspace above Mt. Aleph, and the combined golden beam of realized Alchemy, the Golden Sun, enters into the mountain below and infuses it, causing it to glow. Presumably, this is the Stone of Sages that has been formed, and its existence as a commodity that may be controlled by humankind is what will allow Alchemy to be used by mankind once again.
It was revealed that the Mercury Adept Alex, apparently aware of the how the process would occur, plotted to gain the power of the Golden Sun for himself; Alex climbs to the peak of Mt. Aleph so that when the Golden Sun appears to form the Stone of Sages, he would be standing in the center of the beam. As the beam's power passes through his body into the mountain below, Alex's body gains immensely bolstered power and near-limitless life, leading to the oft-stated claim that he has gained "the power of the Golden Sun". Alex's plan appears to have worked flawlessly, but the Wise One arrives to inform him that the extent of his powers are incomplete; it turns out that Alex's plan was predicted and prepared for by the Wise One since the time when Saturos' group first raided Sol Sanctum to gain the Elemental Stars. The Wise One used his power to imbue the Mars Star with a sort of customized property, which would end up partially altering what the Mars Beacon that would eventually result would do when it came time to shoot out its beam toward Mt. Aleph. Even though the Mars Beacon shot out a beam toward Mt. Aleph to contribute to the resultant Stone of Sages, the power that could have been absorbed into Alex's body at the top of Mt. Aleph was instead absorbed into Isaac's body over at the Mars Lighthouse. The end result of this is that, while Isaac is most likely a much stronger Adept than before (though apparently unknowingly), Alex now lacks a small but crucial portion of the power of the Golden Sun he so desired, which he would have needed otherwise to attain full mastery of the building blocks of reality. Thus, he is not so powerful as to be the near-equivalent of a physical god.
Then, apparently as the final phase of the process through which the Stone of Sages would become available to humankind, the glowing Mt. Aleph begins to change, collapse, and sink into the ground while the landscape surrounding it is rendered an empty canyon, destroyed apparently by a huge outburst of energy. Alex's fate is left open to interpretation. By the time Isaac's party returns to where their hometown of Vale would have been at the foot of Mt. Aleph, they are greeted by the sight of a desolate, empty wasteland with a single, glowing golden rocklike structure jutting out of its center. The Lost Age ends when it is revealed that though the town was destroyed, all of the townspeople, including Isaac and Garet's families, survived because they were warned by the Wise One to evacuate.
The effects the manifestation of the Stone of Sages would have on the world of Weyard are as of now unknown and can only be speculated. As indicated by a Mind Read-accessed set of lines at Prox not normally accessible in normal play, the Stone of Sages constitutes a great power source that would prompt the power-hungry to fight for control of the stone, and as Mia stated at Mars Lighthouse Aerie, lighting the four Beacons "may create wars and strife". Mind Read-able information in Prox also claims that Prox will immediately get to work on studying the newly released power of Alchemy (presumably the other towns and nations of Weyard would do the same), and in the exactly worded thoughts of the Elder of Prox: "The power to revive the dead... It's an awesome and terrifying power indeed... Eternal life could soon be in the hands of Alchemists everywhere... What a thought!" These various statements and claims have been a driving force of much discussion in the fan community for the many years following the release of The Lost Age, giving way to much speculation over what would happen in Weyard now that Alchemy is restored to the world.
Golden Sun: Dark Dawn, a game set to take place "a generation" down line focusing on the descendants of the original games' heroes, appears set to answer precisely these questions; the world's cultures and nations would have had many years to be reintroduced to the Stone of Sages and its concept of Alchemy, as well as to perhaps have attained a newfound awareness of Psynergy. The trailer for E3 2010 shows that apparently, "something went wrong" with the prospect of the Golden Sun bringing peace to the world, and that now a new dilemma is surfacing, which includes the appearances of dark spheres of energy around the world that are akin to black holes.
While psynergy vortexes do appear in Dark Dawn, the bulk of the action involves activating various alchemical devices which had been left all over the world. The four which are activated are all interconnected as well.
The Alchemy Well is found in Aruthay, in the southern end of Ei-Jei. This device is activated with the power of water, with the Luna Mask acting as a key. It was first activated 10 years after the Golden Sun event, by a mysterious man who also fathered Amiti. It can be reversed with the Arid Heat power.
The Alchemy Forge is located in Passaj, bordering on the Endless Wall. It is activated by fire with a Sol Mask as the key. Activating it also powers up the ancient city, including some glowing walls to make the city a fortress. If put in reverse, with the aid of the Cold Snap psynergy, it opens up a cloud passageway across the Endless Wall.
The Alchemy Dynamo is located in ruins under the city of Belinsk. Activation of this device uses all the elements, and triggered with the Magma Orb. Activating this device calls up an ancient tower which causes an eclipse over much of the lands.
The Apollo Lens is located at the end of the Endless Wall, and is the only device known to deactivate the Eclipse Tower after it had been activated. The light shining in the Apollo Lens area is so bright, most cannot stand the intensity without a shroud, either from Umbra Gear or having enough innate darkness to counteract it.