"That's for me to know and you to never find out," she answers, timing her response perfectly with the moment when the doors open and Donovan glances up from his reading, the small lamp light illuminating his profile.

"Evening, detective," he says. "Heard you might be needing a cab in an hour or so, so I called ahead for you."

All Beckett can do is look at Castle and will her jaw not to drop too hard.

"How did you know you were going to get me to put the work down?" she hisses, nudging his side with her elbow as they walk out to the idling cab parked just in front of the precinct.