“I had plans too, you know! And this may come as a shock to you, sonny boy, but one of them wasn't living with you,” Martin tells Frasier in that first episode. It’s a very moving scene that ends with Frasier beseeching his dad for a simple “thank you” for taking him in, which his dad eventually affords him first, in a roundabout way, at the end of this episode, and then, much more directly, the end of the show eleven years later. Between those two “thank yous,” Martin truly evolves.

But there are a number of constants, like his physicality. Whenever Martin sits himself down in his infamous chair (filthy, ugly, and in complete contrast to the rest of the apartment), Mahoney arches his back slightly, almost pushed down by the weight of the world and his experiences, his losses. Mahoney was only fifteen years older than Kelsey Grammer, but he chose to play him as a visibly elderly man—in his mannerisms, his reactions, his movements. Death is a palpable presence in Martin’s life: In the season one episode, “Give Him the Chair,” he mentions how much he misses his dead wife, still dreaming that she would come to wake him up when he fell asleep in his chair. In season five’s “The Gift Horse,” the boys buy Martin his old horse from his days as a mounted patrolman. Martin’s subdued reaction eventually leads them to the stables where they find their father talking to his old buddy: “We were something, weren't we? Now they're putting you out to pasture and I'm riding the buses. It's fun getting old, isn't it?” In “Deathtrap,” from Season 9, Martin talks to Roz’s daughter, Alice, about death, her hamster having recently passed on. Alice scoffs at Martin, when he insists Eddie, his trusted ten-year-old canine companion, is only a puppy. When she and her mother leave, Martin calls Eddie, a visibly elderly dog, to his lap, holds him tight, and plants a gentle kiss on his head.

Perhaps Martin Crane’s most solemn moment in the show comes in the eighth season’s “A Day In May,” when Martin goes alone to his shooter’s parole hearing. He speaks courteously with his assailant’s mother. During the hearing, the culprit is contrite, but Martin cannot bring himself to express forgiveness—and parole is denied. The look John Mahoney gives the shooter and his mother is complicated, and with another actor, and in another show, it could have easy been one note. Mahoney elevates it to greatness.

It would both be unfair and greatly specious to merely highlight such sober moments. “Frasier” was a sitcom after all—true, it was more eager, and even more successful, than many other sitcoms to play with a spectrum of emotions. However, even though its raison d'être was to make people laugh, the sitcom’s emotional core was about the eleven-year long journey taken by the Crane men to become a family again. Frasier, Niles, and Martin are all too happy to be remain relative strangers at the beginning of the series—slowly, over the course of the show, they excavate their affection for each other like a buried treasure chest.