Rattrap and Dinobot accidentally activate Sentinel, the Axalon's new defense system, before it has learned that the Maximals are friends. Feeling guilty for starting it, Rattrap stays inside the Axalon to shut down Sentinel. Meanwhile, Blackarachnia leads a Predacon mission, trying to break into the Axalon, leaving Tigatron the only one to stop them.

The Maximals detect a Cybertronian probe, and try to contact it.