Our family wasn’t like other families when it came to this lost brother, and how we grieved for him. We talked about him so much growing up that it sometimes felt as though he occupied a more elevated spot in our family’s hierarchy than Lucas and I did. My mother didn’t just grieve for him, she longed for him. I longed for him, too, and so did Lucas, and for Lucas, the longing ebbed and flowed like some internal tide of his nature, rising, raging, crashing into something pathological every few years.

The three of us were born together, triplets. Baby B’s name was Colin, but my mother often called him Baby B, as she had during the pregnancy, and so we called him Baby B as well. It reminded Lucas of a nursery rhyme. Big A little a, Bouncing B, the Cat’s in the Cupboard and Can’t see me. To me it seemed to rely on some simple, undeniable system of categorization. Baby: the very title of what he was. B: his place in the order, after me, before Lucas.

My mother and father had married late in life, and at first hadn’t thought they wanted kids at all. My mother spent her twenties trying to break away from her own family, a dysfunctional cadre of Catholics from Chicago, whose enthusiastic mingling of love and guilt and—sometimes—violence was forever in her memory along with the scratchy sound of Bing Crosby on the record player. She’d had more than her fill, she always said, of the noise and the guilt and the God and the Bing.

When she got married she decided my father was all the family she needed. They did all the things you do when you have no kids: threw elaborate late-night parties, up until dawn playing guitar, reading Edward Abbey and Tom Robbins and Jack Kerouac; the only ones for them were the mad ones, they agreed. They moved from Chicago to Denver to Atlanta to Boston, taking jobs at self-impressed liberal arts colleges, teaching literature courses or working in admissions offices. They spent holidays at the cinema watching Jaws and Carrie, congratulating themselves on how nimbly they’d escaped the life they didn’t want, which dogged them all the time: commercials with aproned mothers and suited fathers and children agog over fat golden turkeys on checkerboard tablecloths. They ate lasagna on Christmas Eve and made a big tofu and broccoli stir-fry on Christmas Day.

But it was on Christmas Day my mother started thinking about kids. The way she always told it, she was watching The Sound of Music. She didn’t like that Maria gave up her goal of being a nun, but my mother, along with Maria, succumbed thoroughly to Captain von Trapp’s stern enchantment, and felt elated when he kissed that lovely governess and sang about his wicked childhood.