Eppes Garage of Math and Suitcases. Charlie chalks calculations, and Amita bitches that he's still not working on his article. Then she and Charlie both explain to David what they're trying to figure out. Amita says they're determining what all the players stand to gain from exploiting the secret, versus how much they stand to gain from protecting it. David crystallizes it: "And at what point does it make more sense to kill you than to pay you off?" Alan stumbles in, looking for sprinkler parts. They're by the hoses. Alan complains that Charlie cleaned out the garage and now he can't find anything. Charlie doesn't respond and instead frowns at the board. "Something's bothering you," Amita shrewdly observes. "Tracy was killed, but the threat she posed still remains," Charlie notes obliquely. How the hell can math tell him that? "It can't. It's stupid. It's psychology, and not math, because Charlie's quantifiers are always made up. It would have made so much more sense for Megan, the psych person, to say, 'They're still acting threatened.' It's disingenuous, misleading, and insulting to say that the FBI needed a mathematician to grok that the threat still remained when a mathematician can't do that -- not in the way that Charlie is purporting to do it!" the Evil Dr. Mathra explains, grading papers violently. His poor students. David wants more explanation. "You know that analogy I gave about the lions and the jackal? Tracy might be dead, but the model is saying that the jackal is still out there," Charlie goes on, by way of not really clearing ANYTHING up. Alan comments about it all sounding like a Raymond Chandler novel: "Movie stars, blackmail -- you've even got the evil twins!" Ah, but which one is sporting an evil goatee? David has a breakthrough and tells Charlie to plug the Alive Andrea into the equation rather than the Dead Tracy. Charlie does, and gets a result of $298,000. The hell? "That's it," Amita says languidly, "she's the missing piece." Megan and David return to the Whorehouse and stand next to Andrea's beach chair. "I was wondering when you'd be back," she smiles up at them.