Murphy is stuck under a soda machine. To make matters worse, everyone else is out at a concert and can't help him! To make matters worse still, who should happen upon poor, defenseless Murphy but an angry scorpion and a tooth-collecting maintenance robot?

The crew of Sealab (along with a vapid gossip-show host, a bear in lederhosen and guest stars Kid 'n Play) star in a sneak preview special for the movie Tinfins, complete with plenty of ads for the restaurant Grizzlebee's: "You'll wish you had less fun".

A grief counselor tries to help the Sealab crew through a hard time.

Marco's illegitimate son applies for a job on Sealab. Can he pass the civil service exam with Debbie and Quinn helping?

Marco died three episodes ago. What's he doing back? Later, Marco and Debbie sing Antônio Carlos Jobim's "Waters of March" in Portuguese.

As it turns out Sealab was built on an ancient Indian burial ground and is now sinking into the ocean floor. The only hope to save Sealab is John Bear, Sealab's resident Native American. But in order to save Sealab Shank's must agree to turn the Mess Hall into a casino which he does. But once the casino opens John Bear still won't stop the sinking (or let Debbie have a lounge show).