The latest species to try, the Protheans, were able to construct the Crucible, but before they could deploy it, infighting broke out between those who wanted to use it to destroy the Reapers and a faction that believed they could use it to control the Reapers; these separatists were later discovered to be indoctrinated.
While the Protheans never had the chance to activate the Crucible, its schematics survived in a Prothean archive on Mars for the next 50,000 years.
Modern Construction Edit
After recovering encryption keys from a Prothean Shrine on Kahje, Liara T'Soni traveled to the Mars Archive to see what she could uncover. While examining the archives in 2186, she found the Crucible's schematics and recognized their significance as a potential means to defeat the Reapers.
Commander Shepard retrieves Liara from Mars and hands over the schematics to the Alliance, which immediately begins construction, a massive undertaking drawing on resources throughout the galaxy. Staggering financial costs are disregarded in the common effort to create something, anything, that could stop the Reapers.mass relays, and were left to speculate on how it would ultimately function. More importantly, before the device could be activated it required one final component: the Catalyst.
As revealed by the Prothean VI Vendetta, the Catalyst is the Citadel, the central control hub of the entire mass relay network. At some point in the past, contributors to the Crucible's design realized that it required a means to massively amplify its energy in order to be effective. The Citadel possesses this capability, and so was incorporated into the schematics.
Before the galaxy could combine the Crucible with the Catalyst, however, the Illusive Man flees to the Citadel and alerts the Reapers to the plan. The Reapers seize control of the Citadel and move it to the heart of their occupied territory, in orbit around Earth. With no other option, Admiral Hackett marshals the galaxy's fleets and sends them to Sol. The Crucible enters the fray with a token defense force after the initial offensive.
While the galaxy's forces wage the final war against the Reapers, Commander Shepard succeeds in infiltrating the Citadel and opening it for docking with the Crucible. In doing so Shepard encounters the Catalyst itself, an entity that resides within the Citadel and manifests as a young human boy whose death Shepard witnessed during the initial escape from Earth.
The Catalyst describes the Crucible as little more than a crude but effective/adaptive power source. In combination with the Citadel and the mass relays, however, it can release tremendous amounts of energy throughout the galaxy. In bringing the Crucible to the Citadel, the Catalyst had come to the conclusion that the cycle of extinction is ineffective to resolving organic-synthetic conflicts and leaves it up to Shepard to find a new solution.
If Shepard chooses to destroy the Reapers, the Crucible fires a red beam of energy that destroys the Reapers on and around Earth and transmits to the mass relay network through the Charon Relay before severely damaging the relays and the Citadel as well. If Shepard chooses to control the Reapers, the Crucible releases a blue wave of energy that brings the Reapers under Shepard's control and also transmits to the mass relay network, damaging the relays but leaving the Citadel intact. If Shepard chooses to merge organic and synthetic life, the Crucible fires a green beam of energy that causes the Reapers to stop attacking, gives organics, synthetics and Reapers glowing eyes and circuit pathways across the body, but also damages the Citadel and mass relay network.
- The classical definition of the word "crucible" is '"a severe test, as of patience or belief; a trial." or "a ceramic or metal container in which metals or other substances may be melted or subjected to very high temperatures." Both definitions are fitting for the superweapon; it is both a test of galactic unity and a project which every race must pour its resources into.
- In The Art of the Mass Effect Universe, it is explained that the Crucible's design is meant to evoke an enormous, rocket-propelled bomb likened to a cross between a Trinity bomb and a NASA space probe.
- The Crucible is visible as a hologram in the background of the Mass Effect 3 main menu. Similar holograms can be seen in the Normandy's War Room, showing the progress of the device's construction as the game itself progresses forward.
- If Mordin Solus joins the workforce constructing the Crucible, he sends a subsequent email to Commander Shepard describing the immense and complex project. He compares the Crucible's construction with the human biblical story of the Tower of Babel, as a metaphor for the co-operation between multiple species toward a single goal.