Sometimes there are no handholds at all. Just when I start to panic, my voice turning shrill at the realization that there’s nothing there, that I can’t go any further, Mack speaks. His voice is calm and full of assurance that I can do this. He reminds me to breathe, to take my time looking, that he’s not in a hurry to get back to our brawling fathers so if I want to hang out for a while, that’s cool too.

He gets me laughing, and breathing again, and relaxing enough that the panic ...