Transformers: Prime/Recap/S2/E12 Tunnel Vision

The Autobot team, having obtained the same coordinates for four Iacon relics as the Decepticons, plan their next course of action. Optimus suggests a dispersal, so they can obtain all the relics simultaneously. Despite initial resistance from Arcee, the New York site, and the relic contained beneath its streets, are selected for Arcee and Bumblebee to scout. Miko volunteers her knowledge of subways and Jack his ability to cover, and they get underway.

Having moved away from Manhattan, Megatron assigns Knock Out the discreet task of obtaining the relic there as well. At a disadvantage without Breakdown, Knock Out is unwillingly appointed an Insecticon partner, along with a small detachment of Vehicon miners. Beyond frustrated with Knock Out's lack of concern beyond his paint job, Megatron sends them off.

In a New York alleyway, Arcee and Bumblebee bridge in. They quickly locate a construction site, their entrance to the vast subway network. As they walk, Bumblebee nearly steps on a third rail, but Jack cautions against its danger in time. A familiar sound echoes through the tunnels—a Decepticon drill, which Miko pinpoints the direction of. She tears off through an access tunnel, Jack in tow. On the other side, they are confronted by Vogel, a sweeper train operator, and Miko constructs a hasty lie that saves their tail. He offers to take them for a ride.

Vogel's personality soon becomes clear as he recounts tales of monsters that creep through the subways—including the mole men, who he believes are amassing their armies. Miko and Jack make an escape through the back of the train, Vogel totally oblivious.

Arcee and Bumblebee find Knock Out's party, but are unaware of the Insecticon creeping up on them. It beats down the duo, alerting Knock Out to their presence. Arcee and Knock Out exchange blows while Bumblebee occupies the Insecticon, and the former makes a grab for the relic—but is halted by an electron prod to the back. Bumblebee is also quickly floored by the Insecticon. Satisfied, Knock Out cracks the relic's packaging and prepares to field-test the device on his new subjects.

Jack and Miko bicker in the tunnel about Jack's sojourn to Cybertron, but are stopped in their tracks by the sound of footprints. It's Vogel, none too happy about being ditched. Miko, capitalizing on the man's conspiratorial bent, gets Jack to tell him the truth. Vogel is enthralled, and they all board his train to meet their friends.

Knock Out's field test is interrupted by the arriving sweeper, and while the Insecticon sidesteps it, Knock Out is ground between wall and train, suffering serious cosmetic damage. The Insecticon takes off after the train, and Knock Out peels out with the relic. Arcee and Bumblebee, now concious, split up to meet the train and secure the relic respectively.

On the train, Vogel reveals that the brake line went out—and that their course is for a dead end. To make matters worse, the Insecticon soon comes into view. Making surprising time, Arcee passes the Insecticon and gets on the back of the train. Informed of the approaching wall, she makes for a turn switch. Trying to turn it, she snaps the lever, and turns to changing the track alignment physically. She succeeds just in time, and, the train safe, she faces her foe. Relying on Bumblebee's previous encounter, Arcee lures the Insecticon into touching the third rail, which instantly kills it.

Knock Out faces off against Bumblebee, who accidentally activates the relic, which clamps onto his wrist. The train barrels in, and heads straight for an oblivious Bumblebee, whom it passes right through without a scratch. It instead clobbers Knock Out, grinding his face on the pavement for a quarter mile. Horrified at his total cosmetic disfigurement, he flees. The relic is revealed to be a phase shifter, which allows the user to pass through solid objects. The problem turns to Vogel, who knows about the Cybertronians. A hasty call forces Fowler, back at base, to deputize the worker as a "deputy of interstellar relations". Vogel is once again enthralled.

Tropes

 * Beauty Is Never Tarnished: Averted. Knock Out is not happy.
 * Chekhov's Gun: Come on, you knew that  was going to come in handy eventually.
 * Conspiracy Theorist: Vogel, natch.
 * Green-Eyed Monster: Miko is still jealous that Jack got to go to Cybertron in "Orion Pax, Part 2."
 * New York Subway: Oddly enough, the only train we see is a sweeper train. Must have been an off day.
 * Runaway Train
 * Sinister Subway: And it's inhabited by albino alligators and mole men, if Vogel is to be believed.
 * Watch the Paint Job: Knock Out. Of course, he gets scratched and beaten up by the end of the episode.