Dr Coy and Akina work together on a new suit of water-resistant armor and other weapons for Zeus. Zeus tests them successfully. Akina fixes King and Fighter.

Megan and her partners, with King and Fighter, prepare to return to the Underwater Stronghold. But so does Quantum/Dark-01. And OmicronPsy not only deploys Dark-03 but also booby traps the Zentrium. As they near the Undersea Stronghold, they encounter Silver-01 and the deadly mini-bots. A huge battle rages. Silver-01 is destroyed. Megan's sub has a few close shaves but makes it to the stronghold, from which Dark-02 suddenly emerges. Zeus engages him while Megan enters the stronghold. Dark-03 also appears. A major rumble takes place with Dr Coy and Akina controlling King and Fighter on manual, and eventually, just as Zeus is engaging Dark-02 in a fight to the death, the once-eaten Quantum appears again.