In the days and months that followed, I tried to find ways to mourn my father. I said Kaddish. I talked about him to my own children. I posted boyhood photos of him to Instagram. But mostly I wrote episodes of “Star Trek: Picard,” through and over which mortality and loss played like musical themes. The truth, I’ve sometimes had the nerve to tell someone who knows how much, in spite of everything, I loved my father, was that I had been grieving his loss since I was twelve years old; it was definitely easier the second time around. When I miss him, I find comfort—just as I did forty-four years ago, when he first left me behind—in his perfect, constant, undiminished presence in my imagination; his voice in my head, anytime I want it; his opinions, his jokes, his enthusiasms and vanities and lies. But sometimes, still, I wake up in the middle of the night, trapped in the broken elevator of insomnia, haunted by the cruelty of mercy and its logic, and by the pleading of the devil in the dark.