After the fall of the Primes, Sentinel's guards have taken Zeta Prime back to Sentinel's tower in Iacon to keep him there. No one in Iacon knew what was going on up there besides Airachnid and the guards.

Zeta felt someone snap their fingers in front of his face, waking him up from unconsciousness. He groggily opened his optics only to see that he was on his knees, his servos were cuffed behind his back and a collar around his neck that was attached to a chain against the wall. In front of him was Sentinel Prime...that traitor...