Doctor Quinn has invented a genetic-hybrid crustacean which wields, in its powerful claws, the power to eradicate world hunger. But only if he can keep those evil Grizzlebee's purchasing agents from getting their greasy manhooks on it. Although to be fair, they're really not all that evil. They're just kinda jerks.
Stormy and Quinn narrowly escape a nuclear catastrophe, only to be trapped in an underwater cave by a thirty-foot, ravenous Great White! And they've only got 10 minutes of oxygen remaining! Actually, in the time it took you to read that, they're probably down to about 9:45... and now it's 9:40... and... you get the ideer.
Sealab is visited by a cherished old friend: Abelard the Talking Whale. Although he can't really talk; it's more like Quinn just makes him talk with a machine. And he's not so much an old friend; he's just some whale that happens to be dying of whale cancer. And a quick word about whale cancer: you don't want to catch it.