When I was 17, my adopted sister accused me of getting her pregnant. My family disowned me, my girlfriend walked away, and I vanished without a trace. Ten years later, the truth finally came out—and they showed up at my door in tears. I never opened it.

I was seventeen the summer everything fell apart. We lived in a quiet suburb outside Seattle, Washington, where neighbors waved politely and kids rode bikes through cul-de-sacs.

My family had adopted Mia Carter—a quiet, dark-haired girl from Romania—when she was ten.

I was twelve at the time, and while we weren’t especially close, we got along fine, the way siblings …