Key to Vector Sigma
| This article is about the Key itself. For the episode that introduced it, see The Key to Vector Sigma, Part 1. |

The Key to Vector Sigma was an ancient device that was connected to Vector Sigma and allowed a Transformer to activate the ancient intelligence. It appeared as a small remote with an overdeveloped power circuit and had the ability to control the robotic Centurion droids that remained in the lower levels of Cybertron and defended Vector Sigma.
Apparently, Beta Maxx's vehicle mode can replace it.
Fiction
The Transformers cartoon
By the 20th century, the Key was present in the hands of Alpha Trion on Cybertron until his home was attacked by the Decepticons who gave the key to Megatron in his quest to imbue five cars with intelligence. Megatron would face some resistance from the guardians below but learned that the Key could reprogram them. He would activate Vector Sigma and give life to the Stunticons. The Key to Vector Sigma, Part 1
When he returned to Earth, Shockwave informed him that the Key possessed a different power on Earth which was capable of destroying it. Megatron accidentally learned, while studying the Key, that it was capable of transforming matter into metal. He began the process of transforming Earth into another Cybertron but was defeated by the Autobots. Silverbolt would later destroy the Key after he forced Megatron to drop it which reversed its effect on Earth. The Key to Vector Sigma, Part 2
Beast Machines cartoon

Using the Diagnostic Drone, Tankor was able to obtain the code that formed the basis for the Key and materialize copies of it. He shot Nightscream with it, which caused the Maximal to turn to technomatter and go insane. The condition was contagious, as anyone Nightscream touched also became technomatter. Pleased with the results, Tankor faked his own death, knowing that Megatron would find the decoy corpse and plunder the Key program from it. The Key Tankor hoped that Megatron would use it to destroy all organic and techno-organic life on Cybertron—including Megatron himself, who still possessed his dragon beast mode. Megatron had the key duplicated and added to his Vehicon drones, who used them to zap a huge vine grown from the Maximals' orchard. The Maximals were able to sever the vine before the effects of the technomatter reached the rest of their plants. The Catalyst
Eventually, after Tankor gave Optimus Primal the key to activate the Plasma Energy Chamber in an attempt to force Megatron's hand, both Megatron and Primal activated their doomsday weapons, apparently disintegrating all three of them, but (thanks to a last-second change of mind from Primal) leaving Cybertron intact. End of the Line
Primal would be resurrected by the Oracle shortly afterward, while Megatron would survive in a purely organic form. Rhinox, however, was lost to the Allspark. Fallout
Megatron later attempted to use the key to turn Cybertron into a technomatter planet but was stopped by Optimus Primal. Endgame Pt. III: Seeds of the Future
The AllSpark Almanac
The Key was one of ten figures that made up the Cybertronian zodiac. Its associated aspect was "secrets" and assigned orbital cycle was Rokuneon. Its constellation forms a key. The AllSpark Almanac II
Prime cartoon

The Key was within the possession of Optimus Prime when he led Team Prime on Earth. When Unicron was awakening within the planet's core, he decided to team up with Megatron to defeat this threat. Before departing through a GroundBridge to Earth's core, he gave Jack Darby the Key, calling it "the key to the GroundBridge power supply" and stating that Jack had shown enough maturity to be entrusted with the device (the Key transformed into a smaller version of itself as it passed from one to the other). One Shall Rise, Part 2 Ratchet later noticed the Key and asked Jack where he got it from; upon being told Optimus had given him the item Ratchet explained that there was no "key to the GroundBridge" and that the artifact was the Key to Vector Sigma, describing it as "one of Cybertron's most important relics." When Jack asked why Prime would entrust him with it, Ratchet answered that it was because Optimus did not expect to survive his confrontation with Unicron. One Shall Rise, Part 3
Once Jack and Arcee reached Cybertron, they began using the key to try to track down Vector Sigma, and it began leading them towards Kaon. Orion Pax, Part 2
Within the Decepticon capital, the key triggered the rising of an ancient portal, which Jack entered while Arcee was otherwise occupied with an Insecticon. He followed the key's signal down to the chamber containing Vector Sigma itself and used it to activate the ancient computer. Despite an attack by scraplets, the Key received the contents of the Matrix of Leadership and Jack took it back with him to Earth, where he transferred his contents back into Optimus Prime's Matrix, restoring the Autobot leader's memory. The Key was then returned to Prime's possession. Orion Pax, Part 3
Merchandise
Diamond Select Toys
- The human-scaled Autobot Matrix of Leadership includes a human-scaled Key to Vector Sigma.
Timelines

- A removable key was packaged with a hollow plastic Vector Sigma, a special souvenir item offered exclusively at BotCon 2007.
Notes
Foreign names
- Japanese: Vector Sigma no Kagi (ベクターシグマの鍵 Bekutā Shiguma no Kagi, "Key to Vector Sigma"), Vector Sigma no Key (ベクターシグマのキー Bekutā Shiguma no Kī)

