I dressed both girls quickly and walked out of the recreation center without letting either of them see how frightened I was. Once we were inside my locked SUV, I started driving toward Denver Children’s Hospital.

Eight minutes later, my phone vibrated.

Turn around. Now.

Then a second message.

Claire, I am serious.

Sarah almost never called me Claire. When we were young, I’d been Claire-Bear. Later I was C, or Sis.