Meanwhile, Megatron had Bombshell make several alterations to Nightbird, removing the limitations Fujiyama had set and boosting her power supply. Many people argue that Nightbird was merely a programmed automaton because of the scene where Bombshell slips some sort of chip into her head and says, "I love warping minds for you, Megatron." Starscream scoffs at Nightbird, who promptly socks him one in return. Megatron separates them and reveals his Evil Plan (tm) -- Nightbird is going to retrieve the World Energy Chip from Teletran-1 for him.
Nightbird sneaks into the Ark with pretty laughable ease, revealing that she is equipped with climbing skills and a grappling hook and line. She doesn't move silently, but so quietly that none of the Transformers or even Spike notice her moving around. She happens across the Autobots' new security system (floor sensor pads installed at the beginning of the episode), and defeats it by magnetizing her feet and walking up a wall and along the ceiling. Sneaking through the base, she finds the chip and rips it out of Teletran, which sets off an alarm and knocks out the lights. She encounters Mirage in the dark and beats him up easily, displaying martial arts skills. When a group of Autobots chase her into a corner, she tries to chase them off by converting her hands into whirling sawblades and throwing them at the Bots. That doesn't work, so she performs a vanishing trick -- whirling around, she suddenly creates a burst of light that blinds them long enough for her to escape (somehow).
The Bots track Nightbird through the countryside as she heads back towards the Decepticon land base she was altered at. Prime hits her with a stun beam, but when Prowl approaches, she jumps up and takes him down. ("She was playing roboto-possum!" says Prime.) Optimus then approaches her, cautioning the other Autobots not to fire at her, since they've promised not to harm her. Nightbird attacks him, knocking him down, when someone shoots her laser sword out of her hand. She leaves the sword and grabs Prime's rifle and takes off, literally jumping off a cliff and disappearing when pursued by the Bots.
At this moment, we cut to a scene of Megatron laughing that "Prime has lost his rifle to little Nightbird."
Starscream mutters, "She's not so hot," to which Megatron responds, "She's hot enough to replace you whenever I choose."
He also comes out with, "She's everything I've always wanted," which is used as support for the small but vocal group that sees Megatron and Nightbird as an item.
Nightbird continues to evade the Autobots, coming up with counters to their every attack, until she's finally trapped in an energy net. In the meantime, Starscream has injudiciously punched Megatron in response to his continued taunting suggestions of replacing Starscream with Nightbird, and been locked up. When Megatron notices Nightbird's capture, he shouts, "We must rescue her and the chip!" putting her first, another little item for the pro-relationship group.
The Decepticons attack the Autobots, freeing Nightbird in the process, and for a moment it looks as though the battle will go to them, no small thanks to Nightbird's defeat of five or so Bots. However, Starscream has freed himself and proceeds to stun Nightbird with a null-ray. She collapses into Prime's hands lifelessly, and Megatron calls off the Decepticons to chase after Starscream.
In the final scenes, Nightbird is locked up by Dr. Fujiyama, while Prime says he's glad that she's deprogrammed. But the final shot, of her angrily narrowing eyes, makes it unclear just how deprogrammed she is.
Nightbird makes no other appearances in the Transformers canon.