Jill, meanwhile, felt her training kick in. She checked her pulse: 98, fine. She drank water. She guided Q away from the mirror when he started whispering to his reflection. “You’re safe,” she said. “You took a drug. It will end.”

It was a damp Tuesday afternoon when Q, a restless philosophy student, decided the universe owed him a shortcut to meaning. His roommate, Jack, a lanky cynic with a penchant for bad decisions, had procured a small bag of dried psilocybin mushrooms from a friend of a friend. Jack’s twin sister, Jill, a pragmatic nursing student with a first-aid kit always in her backpack, was the reluctant third party.

“What did you see?” Jill asked softly.