A dangerous tidal wave washes all the fish up in the trees, which is also a big problem for the poison dart frogs who don't have enough puddles up in the trees for the tadpoles. Luckily, Tweak's new Gup-H is ready to help.
Kwazii and Dashi become entangled in a strange deep-sea creature - a siphonophore - and when a geyser blasts it toward the surface, the Octonauts must stop its ascent before it fatally bursts.
After an earthquake leaves Danny trapped and alone, his claustrophobic nightmare only gets worse when something truly horrifying emerges from the fissures in the ground, forcing him to engage in a brutal fight for his life and his sanity…