Last November, doctors told McQ he had six months or less to live. The choice, he said, became not death over a healthy life, but a “certain outcome” now over a prolonged, painful — and “unknowable” — end.

“I’m not wanting to die,” he said. “I’m very much alive, yet I’m suffering. And I would rather have it not be a surprise.”

In late December, a friend picked up a prescription for 100 tablets of the powerful sedative secobarbital. For weeks, the bottle holding the lethal dose sat on a shelf in his kitchen.

“I was not relaxed or confident until I had it in my cupboard,” McQ said.