A little more digging on the Internet reveals that this isn't the first strip-search prank perpetrated at fast-food chains. There've been a bunch of them (and in real life there was a rash of them in the mid-'90s). But I guess we can't expect that detectives in sex crimes unit would be aware of a rash of crimes in which people are ordered to sexually abuse their victims. The TARU tech says all the calls have been made on phone cards bought at "Valu-Mart," and the cards need to be activated at point of purchase. A click of a mouse reveals the results of facial-recognition work done on security camera feed and comes up with the same guy activating all the cards. There's no mistaking Robin Williams in the security footage, but the detectives focus instead on the ID tag around his neck: Aerodax Labs, and the letters OOK, which could be part of his last name.

Over at Aerodax, we discover that "Merritt Rook" is an audio engineer, who's -- gosh darn it! -- sick today. "Well, we can make a house call. We'll even bring him some chicken soup."

The detectives head over to Rook's place, where an affable, glasses-wearing Robin Williams lets them in and jokes about being arrested for playing hooky. Elliot calls him "Detective Milgram," and Rook doesn't know what he's talking about. Elliot says Rook's the guy who buys all the phone cards at Valu-Mart, which Rook says he gives to homeless people. And when the call to Happiburger was coming in from a library payphone, Rook says he was trout fishing in the Catskills. Corroboration? Sure! Right at hand is a fishing license, hotel bill, and the business card of a diner where he ate his meals. Elliot's all, "Well, that's handy!" and Rook sheepishly says the waitress was sweet on him and wrote her number on the back.

So back at the squadroom, Munch calls her up, and she confirms that he was there for breakfast, lunch and dinner that day. She also says he was after more than the blue-plate special. Next up is calling the hotel to confirm Rook stayed there, and the guy who answers the phone asks Munch to hold. Wondering why they're doing this on camera instead of just having Fin or Chester deliver the news to Olivia and Benson as usual? It's so Cragen can come in and drop some extremely fortuitous personal knowledge about how the EPA isn't allowing any fishing licenses up there for some reason or another (does it really matter?). As the Margaretville Lodge manager gets on the phone to confirm Rook stayed there, Elliot gets a look on his face. So did I, since the manager was clearly Robin Williams deepening his voice a few tones. Elliot whispers in Munch's ear, and Munch asks the manager how the trout are up that way. "They're biting up a storm."