She pointed beneath a row of gauges that meant nothing to Liam, and he saw a knob with four settings: Right, Left, Both, Off. It was set at Off. He stared at it in puzzled silence for a moment. "Where's the On?"

"What?"

"If there's an Off, there ought to be an On."

Seemed simple enough to Liam, but Wy shook her head. "Magnetos are little generators, their own power source. There are two of them, and they're always on. This isn't really an on-off switch, like a"-she cast about for a comparison to something he might understand-"like a light switch. It's a kill switch. Either their power is available to the engine, one or the other or both of them, or it isn't."

"And according to this switch, power from this one wasn't when Mr…"

"DeCreft."

"When Mr. DeCreft pulled the prop through."

"No. But it must have been, or-" She stopped, and added, almost against her will, "I don't get it."

"Get what?"

"Th." She waved a hand, inclusive of the deceased, the Super Cub, the dash. "Bob was even more careful than I am. He never would have pulled the prop through with the mag on."

Liam regarded the knob in frowning silence. "How old was DeCreft?"

"Sixty-five."

"Sixty-five?" He raised an eyebrow and looked at her, something it was getting easier to do.

"Sixty-five going on thirty," she said. "He passed his flight physical every year, including this one."

Liam let that pass, too. The Cub contained two green headphones with voice-activated microphones attached, one hanging from a hook over each seat, and two expensive-looking handheld radios sitting on the backseat, as if carelessly tossed there on the way out of the plane. He looked back at the dash, stooping to examine the switch more closely. "Hey. What's this?"