Justice League (2001)

S3E26 Destroy Seaview!

Admiral Nelson has fallen victim to brainwashing. After securing a crucial energy source, he tries to eliminate Crane and the visiting Dr. Land inside an underwater cave. Once he escapes, he returns to the submarine, gases the crew, and initiates a countdown to blow up the reactor. Will Crane manage to recover in time and make it back to the Seaview before Nelson can carry out his destructive plan?