She locked the door and pushed one of the wing chairs across the room and against it for good measure. She’d go online tomorrow and find some kind of door alarm too. She wasn’t about to have anyone surprise her.

She needed to do something to try and calm herself down, but what? When she was a small child, Lily had affectionately referred to her as her little worrier. It was impossible for someone whose mind didn’t operate that way to understand how debilitating anxiety could be. Whether it was stressing out over schoolwork or worrying about wearing the right outfit to a party, it seemed like she was always overthinking things. One of her earliest memories was her asking Lily how she was sure Santa wouldn’t get hurt coming down the chimney. It wasn’t until Kate became a teenager that her fears started getting worse. She’d lie awake in bed when her parents were out, unable to fall asleep until she heard the chime of the door alarm and knew they’d gotten home safely. Her imagination would run away with her as she envisioned them killed in a car accident or assaulted by a criminal. She’d toss and turn, trying everything to clear her mind of the horrible scenarios it concocted. Then they’d come home safe and sound, and she’d feel foolish—until the next time.

Even though nothing bad had happened, her happiness was tempered by the feeling that she was always waiting for the other shoe to drop. She would lie awake, imagining disaster. Then she learned that if she did math in her head, it helped her to fall asleep at night, her mind too occupied by equations to churn out unlikely, terrifying scenarios.

Blaire was the first person Kate had confided the extent of her anxiety to, one night toward the end of their first year at Mayfield. She was sleeping over, and they were lying in the dark, the house quiet, spilling secrets.

“Do you ever worry about something happening to your dad? Especially with your being so far away?” Kate had asked.

“Not really. What does my being far away have to do with it?”

“Well, um, I don’t know. Sometimes I don’t want to go to school . . . I’m afraid something will happen to my mother if I’m gone.”

She heard Blaire shift next to her. “Something bad?”

Kate sighed. “Yeah. It’s like when we’re all together, I feel safe and good. But when I’m at school, I think about all the stuff she does and how she’s out all the time. Like my dad is at work, and I guess I’m used to that. But my mom helps all those women whose husbands hurt them. What if they hurt her? Do you think I’m weird?”