John poses like Rodin's The Thinker as Karen sculpts him. John complains about how long he's had to hold the pose. There's a knock at the door. Karen runs over and lets Frank in. John seems embarrassed that he was posing shirtless, which is weird, because why was he posing shirtless, but wearing pants? Was that some sort of compromise that he and Karen reached? Because if memory serves, the subject of the original is completely naked. I don't know. Karen realizes that Frank and John need to talk, so she says she needs more clay and leaves. And thus ends the Karen portion of the program, thank God. Frank tells John that they have a serial killer. John has already heard about the killer, who has been dubbed The Mourner due to his penchant for leaving sympathy cards in pink envelopes at the crime scene. Frank says that they are stuck until they find another corpse with a pink envelope. Frank shows John the symbol written on all of the envelopes. John looks at the symbol and stammers that he doesn't understand, but doesn't remind Frank that he has the same symbol on his chest. Frank, oblivious, says that the envelopes contain clues, and shows one to John that says "1857 R Thomas 23." John searches his brain for a connection, and comes up with "Reginald Thomas." Frank says that name isn't on his list of suspects. John explains that Reginald Thomas was the original architect of the Seacouver sewer systems, and that 23 refers to the number of the sluice gate near Lake Union. Frank says that they've got the location, but now they need a day and time. Frank thinks that 1857 might be military time, which translates to 6:57 PM. John realizes that's the time that Gate 23's valves open and fill the outflow tunnel. I've stopped trying to nitpick what John does and doesn't know, because clearly the answer is that he does know what is convenient for the plot, and he doesn't know anything else. Frank and John run out.
Frank and John walk through the sewers, and this set was so leftover from Dark Angel. John says that it's 6:58 PM and the water level is starting to rise. Frank worries that they are too late. John spots a pink envelope hanging nearby, and they run over to find a guy hanging upside down with his upper body underwater. John lifts the guy, and he sputters and spits out water.