And why had she started it? Why had she shot Dad? Because he’d just been told that his wife had some connection to a teenage mass murderer. And he thought of that stray babysitter who kept coming back and put two and two together.

Robin knew Nicola better than anyone else in her family, and this was what she knew: She was April Cooper. Mom knew it. Just like she knew about the safe in the basement—some hidden place where she could hide a gun from her husband and daughter for more than twenty years.

She left her father’s study and headed for the staircase, the basement door behind it. She stumbled down the dark, rickety stairs and into the musty space, knocking into boxes and broken furniture until she finally found the light. She breathed in the moldy air, pushed cobwebs from her hair—this room the neglected sibling of every other room in this otherwise spotless house. It used to scare her as a kid, this basement. She remembered coming down here once with a boy from her seventh-grade class. A football player she’d been helping with math. He’d dared her to come down here, and then he’d dared her to kiss him and she had, just to get back upstairs again. What was his name? Grant something, she thought, her gaze coasting from an old changing table to a toybox to an enormous stuffed bear that she never remembered owning, all of it down here for years. Lurking like ghosts. Like memories.

She saw a clothing rack, hung with her parents’ old Halloween costumes. His and hers surgical scrubs, his and hers pirates, Groucho and Harpo Marx—her parents always a team, inseparable. Though, as she remembered it, the costumes had always been Dad’s idea. She collapsed onto the dusty floor and looked at that costume rack—easily twenty Halloweens’ worth of his and hers outfits, worn once and never again . . . except . . . Robin put a hand against the ones at the end—a pinstripe suit. A pencil skirt and sweater. A fedora and a beret and two fake machine guns. Bonnie and Clyde. Robin could remember her dad bringing those costumes home, when she was young enough not to have understood the cultural reference. Mom had taken one look at them and locked herself in their bedroom.

How could you, Mitchell? How could you?

Young as Robin had been then, Mom’s reaction had stuck in her mind—the drama of it. Robin had always assumed it was because of the guns.