Teleplay by Shane Rimmer Directed by Leo Eaton Edited by Bob Dearberg Original UK Airdate: December 1st, 1968 (ATV Midlands)

"You are mad. Your son is mad. I am mad."

Joe 90 becomes one of the world's leading aquanauts and prevents
an international incident when a submarine breaks down in forbidden waters.

*   *   *

An advanced two-man submarine is damaged through a missile outlet fault which allows an inrush of water. The crew are rescued by helijet, but unfortunately the sub has drifted into forbidden waters and now lies in Porto Guavan territory.

This threatens a tricky international situation unless the sub can be moved without discovery. Joe 90 is therefore given the brain patterns of the world's leading aquanaut, and he and Professor McClaine visit Porto Guava, ostensibly on a fishing trip.

But they attract the suspicions of a boatman, from whom they hire his craft. The Porto Guavan Coastal Control is also suspicious, and sail out to make inquiries just as Joe is under-water, trying to get into the stricken sub. To make matters worse, he is trapped. The authorities, believing that he must have been deliberately drowned, arrest the Professor and the boatman on suspicion of murder.

Joe, however, succeeds in freeing himself and also getting the sub safely away from the forbidden area before arriving at the jail to prove that he certainly hasn't been murdered and that there is no case against his father and the boatman!

* Uncredited.