Holmes and Watson have gone to The Kent Philanthropic Trust. The door-person is confused when they say they're here to see Peter Kent, so Holmes says to say it's about Greek Tetragrams. In the waiting room, Holmes gives a great sigh when Watson asks if something is an original Hopper. All of the paintings in this room original! And they're all very valuable. Except for one, which is a lithograph poster of the Pieta. Or... is it? Holmes goes over and breaks the glass on the lithograph's frame. He pulls out a knife and rips the poster apart to show the actual Pieta underneath. Nice work!
Peter Kent's son rushes in. Holmes says Peter stole the Pieta. And two nights ago, he stole the diamonds! Except that the son explains that his father had a stroke two years ago and hasn't moved since. Holmes tells Watson she was right: Briggs sent them on a snipe hunt. I like the idea that there was a legendary art thief with a fancy pseudonym baffling the police for decades, but it took Sherlock Holmes an hour to solve the case.
Holmes grouses to Watson about wild goose chases. Peter Kent's son didn't want all them to go public, so he let them take all of his father's loot, which they carried home on the subway. The word "court" makes Holmes realize that Carter Averill had a trial, so there ought to be some transcripts with at least some details of the crime. Maybe someone pieced it together! Watson thinks the only reason he's stuck on the copycat theory is because he couldn't do it himself and can't stand the idea that someone could be smarter than him. Well, wasn't Carter Averill able to crack the safe that baffles Holmes?
Holmes and Watson drop the incredibly valuable treasures off at the police station, where Gregson is uncomfortable about this whole thing. They just coincidentally found Le Chevalier's stuff? Right after searching for Le Chevalier? That is their store. And Holmes is not leaving the art tube (which obviously contains the Pieta) with the police; he's taking it home instead.
At the Brownstone, Watson is not okay with Holmes hanging a stolen fifty million dollar painting in their living room. Holmes figures he might as well have a masterpiece around while he studying court transcripts. He promises to bring it back tomorrow. Watson's phone, which is on the mantel for some reason, rings. It's her brother Oren! If this were the IMDB Trivia section, Ids have something about how Lucy Liu player O-Ren Ishii in Kill Bill. Apparently she texted him to say she was coming to dinner with her client. Which means, of course, that Holmes did it. They've been pretty consistent with Holmes's trait of putting things away in weird places. Remember that time he left a bag of chips on the top shelf of a bookcase? Watson complains that she had a code on her phone to keep Holmes out, but Holmes points out that obviously a four-digit code wouldn't present him any problems. She wants to leave him alone, Holmes says "relapse" to force her to keep him around.