The Michigan State University Engine Research Laboratory is usually calm, but by midmorning on this August day, everyone is on edge. Then, a few minutes before noon, assistant engineering professor Norbert Müller gets the call they’re all waiting for: The most influential man in energy research is here to see Müller’s work.

The tall German shouts the news and trots down the cinderblock hallway toward the front door, drawing a wake of colleagues and graduate students. They flood the sidewalk, standing on tiptoe and squinting through the asphalt’s thermal shimmer as an SUV pulls up and a small group gets out. Finally, a tugboat of a man dressed in a blue sport jacket and print tie emerges, and tows his entourage across the parking lot toward the crowd.

Arun Majumdar approaches with restrained economy, as if he has calculated the caloric output of each stride. He steps onto the sidewalk and extends one hand just far enough to reach Müller’s, while the other hand stays pressed tightly at his side. “Good to see you,” he says. Müller, one of the world’s foremost experts in thermal-fluid engineering, shifts from foot to foot as he meets his guest. Until now, Müller has had to support his research with hard-won five- and six-figure grants from multiple sources. Majumdar gave him $2.5 million. In Müller’s world, Majumdar wields immense power. He has hundreds of millions of dollars to dole out to high-risk projects like the one that Müller is about to unveil. And he’s here to check up on his investment...