“I should probably take my earrings off, huh?” she said, removing her hoops.

“For safety reasons,” said Melissa Bank, her friend from Los Angeles, who had flown in to cheer Ms. Plaza on.

Mr. Stock asked her if she wanted to warm up, maybe hit a couple off the tee first.

“No,” she said, thumping her bat against the turf.

One of the center’s coaches, Mike Belmont, who everyone refers to as Jellybean, flicked a switch and the machine juddered alive. Its metal arm scooped up a grubby rubber ball (it looked like a dimpled egg yolk) and flung it out at 48 miles per hour. It thunked against the backstop.

Shooting “Legion,” an X-Men-connected drama that is arguably one of the most visually stunning and mentally baffling shows on television, Ms. Plaza sometimes found herself “riddled with self-doubt and anxiety,” she said. She plays, Lenny, a former psychiatric inmate, who is now probably mostly human and probably mostly alive.

“I have to read the scripts five times before I can even understand what’s happening,” she said.