Marco died three episodes ago. What's he doing back? Later, Marco and Debbie sing Antônio Carlos Jobim's "Waters of March" in Portuguese.
Marco's illegitimate son applies for a job on Sealab. Can he pass the civil service exam with Debbie and Quinn helping?
Zombies ravage Sealab as Debbie plans her (fifth) 30th birthday party.
A grief counselor tries to help the Sealab crew through a hard time.
A team-building exercise goes horribly wrong when the Sealab crew are attacked by Chupacabras.
Stormy's meddlesome inquisitiveness uncovers Shanks' membership in a world-controlling society.
Tornado Shanks declares Sealab a sovereign nation in order to be his own tax haven. A wave of secession fever sweeps through the entire crew, with a half-dozen nations declaring themselves independent in a few minutes; with the help of two British businessmen, they are all soon armed with missiles allegedly loaded with nuclear warheads. When push comes to shove and every Sealab nation declares war on every other one, however, the nukes all turn out to be duds.
Quinn, White Debbie, and "He Who Smokes Bitches" Stormy Waters venture deep into Tornado Shanks to destroy a malignant tumor in Captain Shanks' head.
The last of Captain Shanks' brothers (who are all named for mythical Greek heroes) dies from a heart attack while taking a dump; all the while, Hesh and Debbie Dupree get married.
Dr. Quinn teaches Debbie Love's class of 4th-graders including Fatass McBlobbicus, while having to deal with Tornado Shanks' warped and unscientific view of education. The classic story "The Scarlet Ibis," by James Hurst, is ripped off as part of a classroom discussion of death. All the while, cuts are made between Debbie Love's classroom and the spa Love is visiting, creating a series of double entendres.
A delivering mishap and some dishonesty on Sparks' part pockets Sealab a brand new Asteroid Smasher/High-definition Television. Unfortunately, the ASHDTV was supposed to go to Spacelab so they could destroy an asteroid hurtling towards the earth.
