WHEN IS AAC “IK E” Perlmutter, the chief executive of Marvel Entertainment, showed up at a West Palm Beach, Fla., law firm on Feb. 27, 2013, he had no idea he was about to become victim to a caper worthy of one of his company’s comic books. Israel-born Perlmutter, 73, guards his privacy like Iron Man does his arc reactor, avoiding photographers and refusing press interviews despite steering Marvel through bankruptcy and selling it to Disney in 2009 for $4 billion. That winter day, Perlmutter arrived at the firm to answer deposition questions on whether he quietly had funded a lawsuit against his nemesis at a swanky Palm Beach residential community over its tennis courts. What Perlmutter said, however, wasn’t as important as what he and his wife, Laura, were touching. Because as a judge later would conclude, his presence was part of a plot to secretly harvest his DNA.

Only about a dozen states have laws governing unauthorized collection and testing of a person’s genetic material. Florida is one of them, and now the mysterious and powerful Perlmutter is putting the law to use and claiming a conspiracy that stretches from those tennis courts to courtrooms in New York and Florida. This plot-twister might have begun as a petty feud among aging rich guys, but it now has grown to include Marvel itself, celebrity secrets and even a bit of science fiction.