Umi no Triton EP17 - Vanished Remains of the Tritons

Suddenly a submarine volcano erupts, as if to obstruct Triton's way. Without doubt, it is Poseidon's doing. A scientist who was investigating submarine resources gets injured in the eruption. Triton saves the old scientist and takes him to a nearby island. This island was also created by the eruption of a submarine volcano long ago. In a cave, Triton and the old scientist find wall paintings depicting the history of the Triton Family. Triton gets very excited, but Poseidon comes to attack them again. He explodes the island again to destroy the remains, and he even takes the life of the old scientist.