“Emma, what is it?”

“I found a key.” Her voice sounded very far away or maybe it was that her pulse was beating a timpani in her temples. That odd smell she’d noticed that very first day fumed around her face and up her nostrils, and her mind conjured not only of smoke and late-night bars but of earthy peat and fire-blackened logs and expensive decanters and nice cut-crystal tumblers. “It fits. I got it open.”

“Oh, my God. Is there a unit? Is it on?”

“Yeah, there’s a unit. There are two, actually.” Only one looked familiar. But there was other stuff crammed in here that also looked familiar—and made both no sense and all the sense in the world.

“What? Two? Well,” Will amended, “unless he decided to mount a second unit that could transmit GPS. Those are pretty new, though.”

“I don’t think that’s it.” ELTs were of a type: thick, bulky orange rectangles bolted into place from which there were normally two wires. One was for the antenna, the other fed through the body of the plane to an audio alert and remote switch on the pilot’s side of the cockpit. “Will, do you remember checking the remote switch?”

“For the ELT? On Burke’s side? Yes, I told you it’s on. Why?”

“Because the unit’s off.”

“What?” The word was flat. “The unit is…”

“Off, Will. As in it’s not on. The main rocker switch is set to off, and there’s no readout on the display.”

“But that…he would’ve had to…”

She waited for him to finish and, when he didn’t, she did it for him. “He turned it off, Will. Burke turned off the ELT before takeoff. But this other unit?” She studied the digital readout. “It’s active.”

“What’s the frequency?” After she read out the numbers, he said, “That’s not right. Standard for search and rescue is four-oh-six megahertz.”

“Well, that’s not this.” She had an idea why, too. “Will, remember when we were talking to Scott about how they’d find us, and you mentioned a flight plan? Well, I don’t think Burke filed one.”

She waited while he absorbed that. “Because he thought he would be VFR, not flying by instruments,” he said.

“No. I don’t think he wanted a record of his exact route.” That also explained why he’d turned off the main ELT but left this secondary unit, set to an entirely different frequency no one would think to monitor, active.

“But that makes no sense.”

“Yeah, it does.” Reaching in, she pulled out a very large, very heavy block wrapped in opaque plastic and secured with industrial-strength duct tape. When she did, she heard a tiny slosh of liquid and a slight chik of glass. Liquid dripped from the block. Of course, this wouldn’t have completely frozen. The really good Scotches, the ones designed for a celebration, were about seventy percent alcohol. Turning her light into the cavity, she remembered what Burke said about installing that new belly tank so he’d had plenty of fuel, which she’d found odd. Why bother with bladders of extra gas if they had all this extra fuel?

Because. Who said a tank could carry only fuel?

“Emma? Why does it make sense?”

“Because.” In the light, the blocks were brighter than snow…and those bricks of bills looked awfully, awfully green. “It depends on who you’re flying to meet.”