Franko leads them over to a picture of Hitler, which turns out to be a collage using yellowed papers full of scientific scribblings. "So none of these have ever been displayed. You're the only person who's ever seen them," says Olivia, and Franko complains that the contemporary art scene has yet to "fully recognize [his] particular contributions." Hey, that's just an excuse. I mean, Piss Christ got an exhibition, for crying out loud.

Peter says he wants to get the books -- whatever's left of them -- back, and he'll reimburse Franko, who says it will take him a while to dig everything up. "But you should also know the collage is for sale," he adds, and then withers under the disapproving stares from Peter and Olivia, and offers to "donate" it.

So Walter stares at the Hitler collage: "Your grandfather was a fan of modern art. But I don't think he would have appreciated this." Peter says he's sorry. "Apology not accepted," says Walter quietly, and I can't think of anything he has said in anger to anyone to date on this show that felt as harsh as that. Peter slinks away while Walter pulls up a chair to sit on, and then at least sees the bright side: "Of course, this means the perpetrator didn't get the formula from the books." So then how? Especially given that the formula had his father's signature in it?

That's when Astrid strolls in to say there's no match on the killer's DNA, which Walter glumly greets as more bad news, and Astrid explains to Olivia that Walter got some DNA from the partial fingerprints: skin cells in the oil. "Not my best work, I'm afraid. The telomere degradation suggested that the man was over a hundred years old, which is fascinating, but not a likely possibility," says Walter, who must really be in a bad mood if, after all the science-gone-haywire on this show, he refuses to entertain the idea that a killer might just be a really old dude. And then Peter starts to put it together when he asks Walter if the toxin could be programmed to target more than one genetic trait. "Das herrenvolk. The master race. The Nazis' ultimate goal. The purification of the German people and the white race," says Peter. Nazi science for a Nazi agenda, says Olivia. Well, what else?

In some back alley under an overpass or something, populated by homeless people in tarped-over crates and fires burning in barrels, the Nazi strolls into an open area and sets one of his Sterno cans down, as he's confronted by a surly ... hobo? Can I use that word? I do like the word "hobo." I realize he's not actually carrying a bindle, but ... ANYWAY, the Nazi says, "I'm conducting a test to monitor the dispersion rate of my experiment." He lights the can and invites the hobo to check it out. In a matter of seconds, there's a huge plume of white smoke shooting up and outward. When the smoke clears, the hobo is lying, presumably dead, on the ground. His dog, though, is mercifully still alive. Because you can kill all the people you want on television, but if you start messing with dogs? People lose their shit.