“The next line isn’t ‘Then what is it?’ ” Gus said. “It’s ‘What do you think I think it is?’ ”

“Okay, then,” Shawn said. “What do you think I think it is?”

“I know what you think it is,” Gus said. “You just told me. You think I’m applying for a job with another detective agency.”

“If you already know what I think, why did you ask?” Shawn said.

Gus stared at him helplessly, which made Shawn feel pretty good for a moment. At least he still had the power to twist Gus into knots of logic. He was pretty sure that if he put on just a little more pressure, he could make Gus’ head explode just like one of those movie computers. And maybe that was exactly what he deserved for his betrayal.

Shawn fixed Gus with a steely gaze. “W-H-Y. Question mark,” he said.

Shawn thought maybe he should duck back behind the corner to miss Gus’ brain shrapnel. But the look on Gus’ face suggested a level of distress no greater than mild irritation.

“Really?” Gus said. “Haven’t we been through this a million times? If you feed a computer a nonspecific question like Why? it won’t explode in an existential crisis after pondering the meaning of suffering in the universe. At best it will respond that it needs more information to process the request. Most likely it won’t do anything except sit there until you get tired of waiting and start playing solitaire.”

Gus’ brain had apparently been hardened. No doubt he’d known this was coming. “What if I told you that everything I ever said was a lie, including this?” Shawn said.

“I’d say it was a slight exaggeration,” Gus said. “And I’d also say it’s pretty harsh for you to be trying to make my brain explode when you’re the one who’s been following me.”