Transformers: Prime/Recap/S1/E20 Partners

Aboard the Nemesis, Starscream confesses his sins before Soundwave and claims to have made peace with his position as second-in-command. He goes to the bridge where Airachnid is telling Megatron about one of his indiscretions, a failure to disclose the location of the crash site of the Harbinger, a Decepticon transport ship that crashed on Earth while containing an experimental weapon. Megatron orders Starscream to lead Airachnid to the crash site to retrieve the weapon.

Elsewhere, Arcee stands at Cliffjumper's graveside and talks to her old partner, promising to find the Decepticon responsible for his death.

Meanwhile, Starscream and Airachnid reach the Harbinger crash site, but Airachnid is deliberately cagey about what the weapon is that they're looking for. She's impressed by the fact that Starscream was the one who terminated Cliffjumper, but reveals she knows about the fact that Megatron was planning to terminate him at the Energon mine. They burrow their way down to the buried wreck, and Airachnid accesses the ship's computer to find the location of the cargo. Starscream warns that the signal might alert the Autobots.

Indeed, at that moment, Ratchet alerts Optimus that the base sensors have detected an ancient Decepticon signal.

While searching the ship, Airachnid finds that corridor leading to the location of the weapon ends in a stone wall. It appears that the ship broke in half before crashing, and the weapon is in the other half of the ship. Starscream won't tell her where the other half is, so she binds him in a web and threatens him until he blabs. She leaves him stuck there with the suggestion that she 'might' come back, but runs into the Autobots in a corridor. Forced to double back, she drills her way through the ground and is followed by Arcee, much to Optimus' concern.

On the surface, Airachnid swiftly gets the better of Arcee, but Prime's arrival forces Airachnid to retreat in 'copter mode. Optimus reminds Arcee that trying to seek revenge for Tailgate's death isn't a good idea.

Meanwhile, Bulkhead and Bumblebee resurface with Starscream as a captive, and they're all surprised when the Decepticon says he wants to switch sides and join the Autobots. Optimus, Arcee, and Bulkhead have a brief discussion and decide to take Starscream along, for now.

After locating the other half of the Harbinger, Airachnid pulls the experimental weapon, a staff, from its container.

The Autobots arrive at the stone arch. Optimus believes they should seriously consider letting Starscream join the team because allowing the Decepticons redemption will be important to establishing peace. He leaves Arcee guarding Starscream, and takes Bumblebee and Bulkhead to find the other half of the Harbinger. As Prime's team approaches the ship, Airachnid begins opening fire with the staff, a weapon named the Immobilizer, and freezes Bulkhead in place.

Meanwhile, Starscream tries to convince Arcee that he's safe to let go, but inadvertently lets Arcee know that he was the one who killed Cliffjumper. He frantically attempts to convince her that it was a mercy killing, but Arcee doesn't buy it. She throws down the key to the cuffs so he can free himself and make it a fair fight between them, but he tricks her into getting close enough that he can wound her with his claws.

At the Harbinger, Optimus and Bumblebee take cover behind a rock, but Airachnid burrows underground, coming up behind them and zapping Prime with the power of the staff, freezing him in place. Bumblebee starts exchanging fire with the Decepticon.

As Arcee and Starscream fight, Starscream taunts her by asking if Tailgate was weak like Cliffjumper.

Airachnid gloats over her new trophies, but the dust kicked up by Airachnid's weapon strikes on a nearby rock and gives Bumblebee an idea. He blasts the rock face some more, kicking up a thick cloud of dust. Airachnid sweeps the cloud with the Immobilizer, and when the cloud clears, Bumblebee stands motionless. While Airachnid goes back to talking to Prime, Bumblebee sneaks up behind her and sucker punches her. It is clear that he only pretended to be frozen in order to trick Airachnid. As the Immobilizer is thrown into the air, Bumblebee shoots it and it shatters. Airachnid flees under fire from Bumblebee.

In his fight against Arcee, Starscream gets the upper hand, kicking her around brutally. As he moves in to finish her off, she reveals she's been playing possum and delivers a series of blows that brings him down. Arcee has her blades at Starscream's throat, ready to kill him, when she realizes that they're being watched by Bumblebee. She lets Starscream limp away and collapses.

Back on the Nemesis, Megatron is very furious at Airachnid, not because she failed to retrieve the Immobilizer, but because she left Starscream in the hands of the Autobots. He is concerned about the possibility that that Autobots will gain Decepticon intelligence from Starscream. Megatron swears to Airachnid that she will be punished for deserting his second-in-command, much to her dismay.

At the Autobot base, Ratchet has repaired the Immobilizer and used it to unfreeze Optimus and Bulkhead. Arcee has also been repaired, but blames herself for chasing away Starscream.

Elsewhere, Starscream bashes his clamp bonds against a rock wall, shattering them. He realizes that he is now an independent, beholden to no one and flies off to consider his next move.

Tropes:

 * Book Ends: Starscream's opening and closing monologues, with most of the lines exactly the same. The opening concludes with him proclaiming loyalty to Megatron, but the closing proclaiming loyalty only to himself.
 * Ironic Echo: "I'm afraid that information is need-to-know."
 * Nice Job Breaking It, Hero: As Arcee acknowledges, her actions allow Starscream to escape and rob the Autobots of valuable intelligence.
 * Nice Job Fixing It, Villain: Megatron thinks this is the case upon learning Airachnid left Starscream with the Autobots, thus endangering Decepticon intelligence. While that is not the case, Airachnid's actions were the final impetus for Starscream to go on his own way.
 * Playing Possum: Twice.
 * Puppy Dog Eyes: From Bumblebee and Starscream.
 * Revenge Before Reason: Arcee toward Airachnid. Optimus knows that, so he orders her to guard Starscream instead of pursuing Airachnid. Of course, then Arcee learns that Starscream killed Cliffjumper, so...
 * What the Hell, Hero?: Arcee is about to finish a defeated Starscream, but then sees Bumblebee watching her. He doesn't make a peep, but Arcee (and the audience) can see this trope in his sad eyes.