Aboard their stolen Imperial command ship, the leaders of the rebellion discuss possible sites for a base. But they need fuel. They decide to head for an Imperial facility where they can steal fuel from the Empire.

Disembarking, Chopper spots something across the chasm from the landing platform...

A match for his original leg! It's for sale by a vendor in an outdoor market, and Chopper is very excited. But Hera reminds him that his duty is stay with the ship. Once the team leaves, however, the astromech's attention is drawn back to the leg.

He blasts off and heads over the chasm, and excitedly calls the vendor.

An Ugnaught, he kids Chopper about the strut. "Don't worry, I won't charge you an arm and a leg for it," he says. The seller denies that the leg is stolen and wants 500 for it -- but he won't accept Republic credits. "You're wasting my time," he tells Chopper, and tells him to leave.

When the Ugnaught turns his back, Chopper sees his opening. He grabs the leg, turns for the Ghost...and watches as it takes off, the fuel mission a success.

The Ugnaught chases after Chopper and calls over some stormtroopers. They give chase and call in the theft, noting that a rebel unit just pulled off a heist.

Chopper heads to an Imperial cargo ship looking to hide. He's safe for now, but the Imperials are on alert.

Meanwhile, an inventory droid reports in with the captain. He informs the officer that the nav computer is off calculation by .002, prompting the captain to scold the droid. He orders him to go log the manifest.

The inventory droid notices an unsealed hatch. He moves in to investigate.

Chopper evades the droid for a time, but eventually comes upon a locked door and is caught. The inventory droid introduces himself as AP-5. He knows Chopper is not on his inventory list, and deduces that Chopper is a rebel and stole the leg.

Again Chopper flees, and AP-5 gives chase. "You can run but there will be no escape!" he says. Finally, Chopper threatens the droid with a spark projector. They begin to talk, and both reveal that they served in the Clone Wars. The situation calms, and they walk together.

The astromech tells the story of how the Y-wing he was serving in during a mission over Ryloth was shot down. He avoided the scrap heap by being rescued, which AP-5 has a hard time believing. Chopper shows him an image of Hera, and AP-5 is impressed.

AP-5 explains that he was reassigned from navigation to inventory after the war. While he took pride in his war responsibilities, he does his new duty as commanded. Though his Imperial supervisors continually disrespect him, he will not disobey his orders. Chopper says there are other options -- like free will.

He admires Chopper's fortitude, but seems resigned to his fate. Suddenly, the captain radios AP-5, screaming at him. "Where's that manifest?!" He tells him to keep an eye out for stow away rebels. AP-5 responds by saying he has seen none. With that, Chopper readies his spark weapon...

...and blasts AP-5's restraining bolt. The inventory droid is free. Chopper has a plan: lure the crew into the cargo hold and jettison it into space.

The captain catches up with them. He demands the manifest and readies a new restraining bolt. Chopper attacks him with his leg, and when the Imperial calls in that he's captured a rebel droid...

...Chopper zaps him.

Stormtroopers in pursuit, Chopper leads them into the cargo hold. He zooms away, heading back toward the ship. The astromech ricochets from wall to wall and comes in for a bumpy landing. AP-5 helps him up and seals the door.

The Ghost arrives back at the rebel fleet and finds it under attack. Ketsu is there to help, but this will not be an easy fight.

Now in the cockpit of the Imperial cargo ship, Chopper and AP-5 argue about who is captain. Chopper plugs into the computer and sets course for the fleet. He calls AP-5 his friend, which gives the inventory droid pause. Finally, Chopper contacts Hera.

With the fleet under attack, Hera says they're going to the Yost system. AP-5 interjects. "The Yost system will not be safe for your friends at all," he says. The Imperial fleet is waiting there. It's a trap. Hera asks how they know, and Chopper reveals that he stole an Imperial freighter. AP-5 readies new, safe coordinates.

But they are not alone. The captain is on the ship, as well. "Your rebel mutiny is over!" he says. AP-5 thanks the captain and says he's been taken prisoner. The diversion works, and Chopper attacks the Imperial.

As AP-5 prepares to transmit coordinates, he's blasted from behind. With his last bit of strength, he sends them through.

Enraged, Chopper charges the Imperial and lands a knockout blow.

As AP-5's power fades, he tells Chopper, "I won't forget you, my friend." The rebels arrive at the planet, which is free from Imperials.

But this is not the end of AP-5. He wakes to find himself fully repaired. Sabine replaced his thermo sensors with those from the leg Chopper stole.

Yes, Chopper sacrificed his replacement leg for his friend. "I knew you had a malfunctioning logic circuit!" AP-5 says.