A Wolf in the Fold is the eighteenth episode of the Beast Machines TV series.
Far beneath the abandoned underground civilizations of Cybertron, the Maximals are hanging out, enjoying a breather, happy to have Silverbolt back. Even in their victory, they can't forget the lost Rhinox, however. Silverbolt can't share in the joy; for him, things are not the same. Blackarachnia assures him he'll adjust, now that they've got a moment to relax. Naturally, the entire planet begins shaking just then.
On the surface, a number of gigantic claw-ended tentacles are coming out of the big floating head, and smashing their way into the planet's surface. The Maximals head for the surface, as green pulses of energy pass from the tentacles and along the corridors. One passes through Silverbolt's foot as he runs, and activates some sort of spider-disk-device thing that seems to burrow out of his back. The device immediately shoots him full of some nasty-looking red stuff, causing his eyes to twitch and glow red. Cheetor stops to check on him, resting a hand on his shoulder, and promptly receives a dose of the same red stuff.
As the Maximals arrive at the base of one of the tentacles, the red stuff is quickly passed along: Cheetor steps on Rattrap's tail; Rattrap high-fives Nightscream with a suggestion to attack the big floating head; Silverbolt puts his arm around Blackarachnia.
Optimus hands out attack orders to the group, only to be met with increasingly argumentative comments in response. Within seconds a furious, senseless argument is underway. Optimus's attempts to calm the group are met with rebukes; unable to reason with the group, Primal finally rockets off alone.
A laser blast scatters the Maximals, as Thrust arrives with Cycle drones. Optimus sees the battle below, and turns to help — but one of Cheetor's reflected bolts severs a tentacle. Optimus takes the flailing thing head-on and falls, till another of the gigantic tentacle scoops him up.
Thrust and company, meanwhile, head underground. Cheetor says they have to stop them before they find their base; the others disagree, of course, but Cheetor shouts them all down.
Inside the big floating head, the disembodied Megatron greets Optimus. He's invited him here for a little chat, with the ground attack merely a way to get Primal's attention. Megatron materializes as a ghost data head, telling Primal that they both want the same thing: harmony.
The Maximals, meanwhile, run down the Cycle drones and trash them, then quickly resume arguing. During a brief lapse, Silverbolt soberly concludes that he should never have returned. He flies off, and Blackarachnia mocks him for running away from his problems. And the arguing resumes, as does the fighting: Thrust arrives with more drones.
Back in the BFH, Optimus and Megatron argue the merits of free will versus chaos, harmony versus individuality. Primal is distracted by the image of the Maximals fighting, however, and leaves.
The Maximals, meanwhile, are fighting the drones less and less, and increasingly fighting each other. Cheetor has what alcoholics would refer to as a moment of clarity, realizing something's amiss. But it's for naught, as the infighting continues and sucks him back in as well. Thrust sits back to enjoy the show.
On the surface, Silverbolt approaches one of the giant tentacles, and discovers the spider-thing on his back, which he plucks off with fury.
Primal arrives, and knocks out Thrust with one punch. He orders his troops to stop, but they attack instead, and in short order Primal is infected with the red stuff as well. He joins in the fighting, till Silverbolt arrives. He tells them they're infected with a virus, and somehow manages to calm the group.
Rattrap examines one of the giant tentacles, and finds they're sending an activation signal to trigger a pre-planted virus hidden in Silverbolt. It has "an adrenalin booster, a neocortex suppressor, and a shut-off on the self-diagnostic! And it's contagious." It's apparently a variant on the old Hate Plague, and it can't be counteracted.
Megatron makes his move. Waves of energy pour down the tentacles, rattling the ground and alarming the Maximals. Primal has an epiphany, that they can somehow "work together" to rebuild their neural pathways. Megatron's energies, meanwhile, are sending huge seismic disruptions through the tunnels, collapsing the ground out from under the Maximals. Falling, the group manages to latch onto one another, and one after the next they cured. Optimus lifts the oddball chain to the surface, where they land.
Rattrap's happy to be a team again, but Silverbolt is more angsty than ever over his role in the whole affair. The Maximals hold no grudges, however. The tentacles retract into the BFH just then, the plan apparently failed or over or something. Blackarachnia laments that they were turned against each other. Primal muses that Megatron didn't create the conflicts, only magnified them, and wonders disbelievingly if Megatron might be right. Far above, the BFH has a good chuckle at this thought.