Titre original : From the Bottom of the Wave
At the EFA's underwater energy base, something is attacking it. They ask Gravion to investigate. Leele goes there, and they lose contact with her. The others investigate. Eiji takes Una's place. The Zerivire attacks at this point. Toga finds Leele and rescues her, only to be confronted by some mini-Zerivire. Toga forces Leele into another room while he battles the Zerivire alone. Meanwhile, just as things were looking hopless outside, the rest of the Gravion arrives. Eiji finds Toga lying on the ground, with his head in Leele's lap.
After the rescue, Gravion is formed and then attacks the Zerivire. Toga has lost his sight due to lack of oxygen. However, Leele goes to him and guides his hands.
Later on, Toga recovers at the base.