Disclaimer: I don't own a thing. A.N. Today's prompt comes from Kitschgeist: Dubious and questionable memory. Thank you! My mind was empty for a long time, then I decided to blatantly steal a plot point from another mystery I read (the detective was Dickson Carr's Bencolin). :D

"But Holmes, how can that man be the thief? He's the only one with a confirmed alibi! He was at the casino all along, miles from the crime scene," Watson pointed out, frowning. His friend never forgot a case's detail, much less something this significant! Was he unwell?

"And if he'd been playing cards, I would have excluded him. Because everyone would be staring at the other players, trying to guess how good his hand was. But he said that his vice of choice is the roulette. You know more about such games than I do, my dear, but find me someone at that table staring at anything else but the hypnotic rolling of the ball, and I'll owe you ten pounds," the detective challenged with a grin.

"Don't encourage my betting streak," the doctor replied, shaking his head.

"You're not a saint, old boy. Given where we are, I thought that keeping bets between ourselves was the best I could hope for, tonight. And if you manage to prove me wrong, I will have precious data. But if you can't…A boisterous arrival will make sure one's noticed, and then – when everyone else is engrossed in the game – just as long as one doesn't trample anyone, slipping away quietly is easy. You said, 'miles away', but there are shortcuts that reduce that greatly. The theft was planned. Our man would definitely have mapped the route. Afterwards, if he came back without raising a fuss, everyone would swear he'd been there all along."

Watson's eyes lighted with understanding. "It's not very fair to make a bet you know I can't win, Holmes," he remarked, with a half-smile.

"Well, if you give up, I hope you'll help me ensure our criminal confesses," the consulting detective said.

"Do you really need to ask?"