Professor Ericson, an expert in gravity, has invited Dr. Quest to visit him at his home, Raclef Castle in Norway. There, he will demonstrate a spectacular achievement: the Ericon Bar, an anti-gravity device! Sinister forces are at work to steal the device and the notes that describe it: Ivar is the mastermind, and Dietrich Sorensen is his henchman. Dietrich is disguised as one of the gargoyles that adorn the castle parapets. Using his acrobatic skills, he can come and go as he pleases from that perch. After the demonstration, when everyone is asleep, Dietrich enters the house. Race surprises him, and he can't get the plans from the wall safe. But he can get the bar, which he takes to Ivar. Instead of paying him, Ivar orders him back to his perch. Dietrich is not happy about this, and promises Ivar "he'll be sorry". But it's Dietrich who is soon sorry. Ivar escapes to the fjords with the bar (stealing Dr. Quest's boat). Dr. Quest pursues in a helicopter, and sees the submarine
Elenco: Tim Matheson , Mike Road , Danny Bravo , Don Messick .