The episode opens with someone preparing to show an apartment to a couple. The someone -- let's assume they're a building manager until the show or the closed captioning says otherwise -- tells the couple that the previous occupants moved out in kind of a hurry, but that in no way detracts from the charm of the empty apartment. Ah, but I'm thinking the blood splatters all over the walls might. "Oh, my God," says a woman whom we shall never see again. "Call 911."

Cut to Brass viewing the scene. To give a brief description of the setting: imagine your typical boxy rental apartment -- plain white walls, melmac cupboards in the tiny kitchen, dingy beige pile carpeting. Now imagine setting a blender in the middle of the apartment. Fill the blender with approximately four liters of blood. Neglect to put the lid on the blender. Then hit the "puree" setting. The result? The apartment. Brass surveys the apartment and mutters, "I worked in a slaughterhouse one summer, looked a lot like this." Not one for living in the past, he continues, "The lease is in the name of one Clifford Renteria. He lived here with his girlfriend 'til they snuck out in the middle of the night." Of course they did. When you know you're not going to get your security deposit back, why bother with the fuss of giving notice? Gil points out that the blood on the wall could be not-human. "Deer, sheep, llama," deadpans Brass. Gil continues, noting that perhaps someone went hunting, brought back a deer, and decided the prudent course of action would be to butcher and dress it in the apartment. As he's speaking, he's dropping a blood sample in what looks like a home pregnancy kit -- only one that tests for human blood. Really: it has the little window where you drop the sample, and a diagram indicating human vs. non-human results. I wonder what enzyme the test might be calibrated for -- presumably, such a test would look for a chemical reaction that takes place only in conjunction with something in human blood. Sadly, most of the legwork I did on Google only talked about using polymerase chain reaction (PCR) testing to suss out unique human DNA markers, so I suppose my question goes unanswered. Anyway. Gil surveys the apartment, apparently performs a series of complex geometric calculations in his head to calculate the surface area of the apartment and the volume of blood required to cover that area, then notes, "The human body has eight quarts of blood. So whomever our victim is...is dead." Brass does not look surprised.

After The Who and an interminable series of CBS promos, we're back in the apartment with Gil, Sara, and Warrick. All three are clad in baggy blue jumpsuits. Warrick is spraying down the place with luminol, and once he's done, Gil closes the blinds. The darkened room glows under a virtual blanket of blood. Sara opines that it could be a multiple, then notes she's still acquainting herself with the scene. Warrick jumps in, noting the few darkened areas on the carpet that are not glowing; he thinks the dark areas are the real evidence. Gil points to the long dark block where, presumably, the couch was, then cautions, "We have thirty seconds 'til this luminol disappears." Sara begins snapping pictures while Warrick continues to try to identify what may have been lying on the carpet. He calls Gil over, and they look at a long, rounded area. "It looks like an electric saw," Warrick says. He and Gil both look up from the splotch and at each other. "High velocity, small spray," Gil muses. The splotch fades away. It's a metaphor! I just don't know for what.