THE AUTHOR WITH HER HUSBAND AND THEIR TWO YOUNG SONS.

THE CURIOUS THING about identity is how little thought one gives it until it changes. In May 2014, I boarded a plane from London to Jamaica under the complacent delusion that I was setting off on an ordinary family vacation. We looked much like most other families on the plane except perhaps that I was white and Tony black and our two young sons fair but olive-skinned. Otherwise, we were largely unremarkable.

We stayed in a beach cottage on a slender curl of empty sand in a little fishing village we loved called Treasure Beach. Day 10 dawned as every other had, to a cloudless Caribbean sky. Tony strolled down to the beach with a mug of morning coffee, and Jake, 4, followed in his pajamas, to paddle near Tony’s feet at the water’s edge. I began yoga stretches on the deck of our cottage, while Joe, 3, played inside.

Glancing up minutes later, I noticed a child’s head bobbing in the sea. I scanned the deserted scene, wondering where its parents were. When I realized it was Jake, panic flew me to the beach, but Tony was already in the ocean and had our son in his arms. But he was also calling for help. I plunged in, took Jake, and fought the current to swim him back to shore. With Jake safely on the sand, I turned, expecting to see his father wading out behind us. But the riptide that had swept Jake off his feet was sucking Tony out to sea. This tranquil little beach assumed the sudden frenzy of an emergency scene from a disaster movie. People were streaming onto the beach from houses on either side of our cottage, hurling life rings, screaming for help. As I paced frantically, three fishermen swam out to Tony and gathered him onto a life ring. I stood waist-deep in the surf, took the long rope tethered to the life ring, and hauled the knot of exhausted men ashore.