Like many kids of his generation, Jeff Mills was a comic geek. Growing up in Detroit in the 1960s and ’70s, he pored over the adventures of Silver Surfer, Fantastic Four and Black Panther, among many others — but one series in particular left a lasting impression.

Marvel’s “What If” anthology, which debuted in 1977, imagined alternate timelines in which, say, Dr. Doom became a hero or Captain America was elected president. The multiverse may now be thoroughly embedded in popular culture, but at the time, it was “the most mind-twisting thing.”

“If you’re a young kid, and you begin to think: OK, so what if this scenario was different, and then what if that scenario was different?” he says. “You just find yourself in a rabbit hole.”