Warrick's fairly grossed out too. But he manages to rise above it and point out that there are indentations in the carpet; Catherine's convinced they'll have to go back to the house and put the rug in its original context. What, in the West Faecaltorium?
Cut to Donna standing in the foyer, warming up for a grand mal hissy, then getting deflated when Warrick hands over the warrant on his way up the stairs with the rug. Donna's enabler friend is busy yammering about how disrespectful solving Bruce's murder is for The Widow Eiger, and she should sue the city for having the nerve to treat her husband's killing like a crime. Warrick doesn't even turn around.
Unfortunately, putting the rug back in Bruce's office doesn't help, because the rug doesn't really fit the room. Or as Gil asks, "How do you explain a handprint half-covered by a wall?" Catherine points out that the rug could have come from someplace else, and Warrick replies, "I was going to say the same thing, but this rug has eight divots. It fits perfectly with this desk." "Think outside the rug," Gil advises. Good to see that he's back to his usual Zen self. Well, good for us -- Warrick's rolling his eyes in frustration. Catherine muses, "A man with secrets needs a place to hide them," and from thence it's but a camera pan to the wall of wood paneling that doesn't quite seem right. Gil notices the panel that has a seam, pushes on it, and reveals a low-slung passage one would have to crawl through to enter.
We get a shot of the expressions all three CSIs wear as they peer down into the passage. Warrick is the first to close his mouth and speak. His words: "Get the hell outta here!" We then head through the passage; Gil and company emerge in a nursery that gives every impression of being decorated by Ken Kesey's Merry Pranksters for a race of giants. The background music supervisor ups the ante on the creepy kiddie music, just in case a nursery only the Joker could love didn't have you instinctively recoiling against the possibility of whatever infant it contained. Eventually, someone flips on a light. Catherine says admiringly, "Just when you think you've seen it all..." "People lived in fear of this guy?" Warrick asks incredulously. "Imagine the fear he lived with," Gil responds.
For those of you just tuning in now, this episode is still fraught with perversion. At least, the bumper reading "DUE TO MATURE THEMES, VIEWER DISCRETION IS ADVISED" implies as much.