Chaos Emerald in their possession to track down the others on the ARK. They infiltrate Eggman's base, boarding his shuttle shortly before it launches into space. Knuckles' Master Emerald shards are spilled along the way, and he leaves to collect them. He fights Rouge again, but when he saves her from falling into a lava pit, she relinquishes her shards and he restores the Master Emerald. On the ARK, Tails reveals he has made a counterfeit Chaos Emerald to destroy the Eclipse Cannon. As Sonic is about to use it, Eggman tells him that he has captured Tails and Amy, forcing him to return and rescue them. Sonic tries to trick Eggman with the fake Emerald, but Eggman sees through the plan and jettisons him in an escape pod rigged with explosives. Tails, thinking Sonic is dead, fights and defeats Eggman. Sonic uses the power of the fake Emerald to initiate "Chaos Control" and escape; Shadow is sent to intercept him. Regardless of who wins the fight, Eggman sneaks away from Tails and Amy with the last Emerald and arms the Eclipse Cannon. The entire colony suddenly starts falling, and a prerecorded message from Gerald is broadcast globally: he programmed the ARK to collide with Earth if the Emeralds were used, destroying it in revenge for the government condemning his research and killing his colleagues, including Maria. Everyone but Shadow works together to access the cannon's core and neutralize the ARK using the Master Emerald. Amy pleads for Shadow's help, allowing him to remember what Maria really requested of Shadow: for him to help mankind. Shadow catches up with Sonic and Knuckles in the core as they encounter the Biolizard, a prototype Ultimate Life Form. Shadow repels it, allowing Knuckles to deactivate the Chaos Emeralds with the Master Emerald. The Biolizard uses Chaos Control to fuse with the cannon, becoming the Finalhazard and continuing the ARK's collision course. Sonic and Shadow use the Emeralds to transform into their super forms, defeating the Finalhazard and using Chaos Control to teleport the ARK back into stable orbit. This depletes Shadow's energy and he plummets to Earth, content in fulfilling his promise to Maria. The people on Earth celebrate as the heroes return home, and Sonic bids Shadow farewell. Development Sonic Adventure 2 was developed by Sonic Team USA, a former American division of Sonic Team, and published by Sega. It was directed