Ah. The 'every now and then' was the clincher. Castle saw Beckett as the kind of person who was fully committed to her work -- even when she wasn't at work. He guessed that she'd spent more of her fair share of weekends at her desk at the precinct, filling out paperwork or shuffling through cold cases. She was obsessed with order, a slave to the law, and a patron of old memories she couldn't escape.

Hey, I should write that down.

"And do what?" he asks, rescuing a flock of orphan olives from the tray that Bar has been so kind to provide.