More secrets behind the Great Disaster get revealed by Michelinie, Simonson and Wood in Hercules Unbound 8 (Dec/Jan 76/77).
The story begins with Hercules, Jennifer, Kevin and David on a raft, getting shot at by jet planes, which appear seemingly out of nowhere. The raft sinks, and David appears to die. Jennifer tells Hercules to go back and rescue him, but the hero is sure David is dead and just doesn't want to bother. This will prove to be a bad decision, not just a jerk move.
While Hercules and company wonder where the planes came from, they get set upon by an army of women. These all prove to be robots, and the group find a large bunker. A voice explains that the attacks were a mistake, that the one who ordered them didn't realize she was dealing with actual living people.
Completely confused, Hercules and friends descend into the bunker and meet Lady Agatha Simms, the voice they had heard outside. Simms was paralyzed in an accident as a child, but her mind proved to be more powerful than most. She got hooked up to military computers, and has spent her life controlling them, playing war games that have become reality.
She is involved in a game with someone she doesn't know, operating off of the Isle of Mann. Simms is not as proficient with her abilities as she likes to think. Thanks to the computer interaction with her mind, she is able to draw weaponry from the past, all the way back to World War 2. But her attempt to pull a PT boat to her era results in her bringing the battleship the Bismarck.
Meanwhile, we see that David Rigg survived and did not drown, even without Hercules coming to his aid. He winds up forcibly "recruited" by some robots.
So it's only a bit of a chronological quandary when Hercules and group reach the Isle of Mann to find out who has been fighting for the past few months against Agatha Simms, and discover it is David Rigg.
The story continues in the next issue.