John Mahoney as Homer in Steppenwolf's production of The Rembrandt Credit: Michael Brosilow

We should have known about John Mahoney. He left plenty of clues.

Only last fall, he appeared onstage at Steppenwolf Theatre, where he’d been an ensemble member since the late 70s, in the guise of the Greek poet Homer at the end of his days, musing in Jessica Dickey’s drama The Rembrandt on mortality in the form of “your fragile, freckled hands and your toenails and your puckered rear.”

He seemed as vivid and irrepressible as ever—old, sure, as any actor entering his late 70s is apt to appear (especially clad in a toga), but still in full grasp of his craft. That carried through the peaceful final act of the play, where in a switch of roles, he played the dying lover of his fellow ensemble member Francis Guinan’s museum guard.

Then, Monday, Steppenwolf announced that Mahoney had died at 77 of complications from cancer. Artistic director Anna D. Shapiro said The Rembrandt, which closed in early November, had come during a respite, but Mahoney went into decline after that.

His castmates may have had an inkling during the production, but there had been no ballyhoo, no milking it, nothing to disrupt or distract from the work.

That was typical of Mahoney, a consummate professional. He was a charitable actor and person who by all accounts gloried in setting up his costars—and never more so than as the cranky former cop Martin Crane in the long-running Cheers spinoff Frasier. He’d play straight man to his sons, played by Kelsey Grammer and David Hyde Pierce, and even to his dog, Eddie, but then he’d walk off delivering a zinger of his own, back to the camera, waving over his shoulder, Eddie at his side.

Mahoney, who was born in England and didn’t start his acting career till he was 37, brought a sense of realism to almost all of his roles. He made unlikable characters seem redeemable, as in the case of the father who obsesses perhaps too much about his daughter in the 1989 movie Say Anything, or the jilted lover who gets a drink thrown in his face in Moonstruck.

He was moaning about mortality even then, of course, but it had a different tone in The Rembrandt, when he spoke as Homer at the end of his days.

“I’m going to see the heavens, find out what’s going on in all that blue up there—what God really looks like,” he said. “Or have I done all that already? Has that already happened? . . . Is this heaven?”

Onstage, at least, Mahoney made it seem so.