Proving Grounds is the forty-sixth episode of the Beast Wars TV series.
The Maximals examine Blackarachnia, using a machine to display her insides. Rattrap is unimpressed with the Predacon, but Cheetor finds the lady's structure to be fascinating. Rhinox finds the location of the shell program that Tarantulas installed in Blackarachnia's protoform to make her into a Predacon. When the test is over, Blackarachnia responds aggressively to Rattrap's suspicion and Cheetor's infatuation, but Optimus Primal orders her to stand down. Frustrated with not yet being accepted, she leaves the Maximal base using a secret tunnel, but Dinobot, spying on the Maximals, watches her exit and follows.
In the outdoors, Blackarachnia reflects on her situation to a stray butterfly. Before she can execute the butterfly, she notices Dinobot hunting her. She leaps through trees and starts to hunt the predator. Soon, she ensnares and suspends Dinobot by her webbing. Dinobot cuts himself free and transforms to his robot mode. He accuses her of being a coward and walks away.
In the Maximal base, Rattrap enjoys a video game, but Silverbolt deactivates the game to use the computers to find Blackarachnia. Rattrap cries over his lost game, while the Fuzor determines Blackarachnia to be in Predacon territory. Silverbolt convinces Rattrap to not report Blackarachnia's irregular whereabouts to Optimus Primal by mentioning Dinobot.
In darker woods, Blackarachnia and Dinobot find each other again. But the spider realizes she has been fooled by a hologram, while the real Dinobot attacks her from behind using a strong tail swipe. The two fire at each other, and Dinobot dodges a falling tree. Blackarachnia runs, but Dinobot blasts down two trees, pinning the widow's legs under two massive pieces of lumber. Before he can carve into her, Blackarachnia is able to grab her gun and fire a shot into Dinobot at close range. With her enemy down, Blackarachnia tries to radio for help, but doesn't notice Dinobot being repaired by his Transmetal 2 energies. Luckily, Silverbolt is already searching for his lady friend, tracing her scent.
The other Maximals figure out that Blackarachnia and Silverbolt are in Megatron's jamming zone.
Blackarachnia keeps her guard up, aware that Dinobot is still hunting her. Silverbolt arrives, and is promptly shot directly in the chest. The two males battle, with Dinobot getting an upper hand. As Dinobot uses his heat vision to slowly burn Silverbolt's face, Blackarachnia fires her machine guns at her lover, announcing the fight is between Predacons.
Blackarachnia tries to convince Dinobot to form a private alliance. Dinobot rejects the idea and stuns her with a beam from his eyes. But Blackarachnia's conversation gives Silverbolt the time to stand up again. Dinobot's attacks, but discovers too late that Silverbolt had created a hologram of himself using the holo-projector. He blasts the Transmetal 2 over the edge of one of those surprisingly common steep cliffs—but Dinobot climbs back up to level. However Blackarachnia fires a missile directly into his face, making sure he won't be able to climb up again.
As the sun rises, Blackarachnia and Silverbolt discuss the conversation about her betrayal that he overheard. She explains it was an attempt to fool Dinobot—a stalling tactic. Blackarachnia decides to leaves the Maximals—no longer desiring to let them distrust her as they do. Blackarachnia tries to leave, but her headbutt harms both Silverbolt and herself. Primal lands and explains that it's up to Blackarachnia if she wants to have the shell program removed. Blackarachnia is surprised to find out Optimus is pro-choice. Blackarachnia agrees to stay with the Maximals, but keeps herself the way she is.