When Kylie woke up, she found that she couldn’t process her thoughts and, the harder she tried to focus on past events, the more elusive they became. She rolled over to face the door, and when she found Stephen sitting beside her bed, she smiled uncertainty. “There is something wrong with me,” she whispered. “I don’t even know where we are…”

Stephen ran his hands through her hair and said, “You are on our boat. We are on our honeymoon. If this all seems confusing, let me get you your medicine. You have had these spells a lot recently, but you always come back to me once you’ve had your...