Then we get a tightly-framed shot of Warrick opening his locker. He goes for his jeans, then just stands there, looking frazzled and overwhelmed. Switch to a side shot; Warrick is slumped on the bench, limp with exhaustion.
Cut to Archie explaining, "The light and the fan must have been on the same battery." Gil replies, "Well, at least Nicky's keeping it together. That's good." We then establish that, thanks to anonymizers, Archie's getting a different IP every time he tries to run a trace on the signal, but he's getting closer.
Sara's also dead on her feet: she's standing at a water fountain, staring at the bubbler because she's gone blank on why she was there. An equally haggard Mia opens her door and calls, "Sara! I got something off your thumb!" Sara bops down the hall and Mia explains, "When you struck out on prints, I ran the DNA through CODIS, hoping maybe the guy was in the system off an open case or a prior felony. I got no straight-up match but --" "You got a moderate stringer match for Kelly Gordon," Sara notes. "Seven alleles in common, and based on the age, I'd say she was his daughter," Mia concludes. Sara compliments Mia on her work.
We soon find out that Kelly Gordon is three years into a nickel at the state pen for accessory to murder. Gil gives Sara a look when she shares this; Sara continues flipping through the notes from the case and says, "The address of the crime scene is 625 Viking Circle -- that's the same street where the messenger picked up the package. It wasn't random." Gil flips through some more notes, and we learn that a Styrofoam cup with Kelly's DNA on it was what linked her to the crime scene and sparked her conviction.
Cut to Brass and Sara interrogating Kelly. That prison must be, like, next door. I bet Liam and Archie spend their lunch hours watching it through binoculars, praying for a prisoner pillow fight or a hair-washing scene. We soon establish Kelly's beef: "My word against a Styrofoam cup, and I'm spending the next five years being traded for cigarettes by my cellmate." There's a pause and she asks, "You're not...re-opening my case. What do you want?" Sara and Brass then shovel in backstory: Walter Gordon took it pretty hard. He stopped seeing Kelly six weeks into her sentence. She snaps, "Seeing your daughter turned into some hood rat's lesbian sex slave can be rather emotional." You know, I had a whole rant here about how childish and puerile I find sexual degradation as a plot device, because it's meant to provoke our prurient impulses without ever arousing any corresponding pity for any of the participants. But let's all skip the rant -- I already made my point -- and get back to the scene: Sara asks why Walter came to see Kelly last week, and adds, "Did you know what he was planning to do?" Kelly asks, "I don't know. What did he do?" Brass says, "He kidnapped a friend of mine, a CSI, and then he blew himself up, tried to take some cops with him." Way to break the news gently to someone whose cooperation you need, Brass. Kelly's very quiet, and she finally asks, "How many did he get?" Brass gives her a shit-eating grin and replies, "We're all still here." Sara reminds them why they're all still there with, "Nick is still missing -- the CSI is still missing. Do you know where he is?" Kelly's face twists into an ugly smile and she says, "That's pretty funny, you guys not being able to find something." Brass tells her, "If you cooperate, we can get your sentence reduced." Kelly's face twists again. She asks if they know what she used to do before she was put away, "back when I was alive. I used to grow things, outside. I was studying horticulture." Sara looks like she's biting back the Dorothy Parker line, "You can lead a horticulture " Kelly continues, "Flowers. My cell mate, Trish, gave me one for Valentine's Day. Want to see it?" She lays out her left arm. Below the crudely tattooed "WHITE GIRL" legend, there's what looks like a daisy carved into her palm. She snarls, "Want to smell it? I hope your friend dies." Sara just looks at her real hard. Well, that showed Kelly.