'''Season 2, Episode 14''':
!The Bishop Revival

15 people suffocate at a Jewish wedding, appearing to have asphyxiated from the inside out. When the Fringe team arrives, Olivia identifies all the victims as being from the groom's side, whose grandmother was a Holocaust survivor - and Walter surmises that they were all killed via their shared genetic traits. Later, a similar mass death occurs at a coffee shop, in which Walter recognizes the victims all had brown eyes, another common genetic trait. From fingerprints found at the scene, they discover the culprit is Alfred Hoffman, a Nazi scientist apparently somehow over 100 years old. Walter realizes that the man likely worked with his own father, Robert Bishoff (a German scientist who defected to the US in 1943 and anglicised his name), to creating a chemical agent that, once heated as a gas, could be used to target any specific trait using DNA from the target subject - especially those not of the master race. Though Walter originally had his father's files on the subject, Peter had sold them ten years earlier; Peter tries to recover the files but finds some have been used by an artist to create sensationalism art, causing Walter to become distraught.

They trace Hoffman to his home, finding his equipment used to create the chemical agent downstairs but no sign of Hoffman. Walter nearly suffocates from an agent left by Hoffman, but Olivia and Peter are able to save him in time. As the FBI search the premises, they find evidence that points to a convention being held to promote world equality. Olivia and Peter depart to try to find Hoffman, while Walter remains behind, examining Hoffman's equipment.

At the convention, Hoffman has replaced the heating elements for the chafing-dishes with his own. Olivia and Peter struggle with locating Hoffman before Walter and Astrid arrive. Walter uses a fogger to distribute his own chemical agent, this time specific to Hoffman, and soon the man is found dying. As the team regroups, Walter fully admits to killing Hoffman, a crime in itself, but Broyles decides to let it go. Later, Peter has been able to recover the rest of his grandfather's work and returns it to Walter; Walter then goes through the files, finding an old photo of his father and Hoffman working together.

!!Tropes found in this episode:
* TheAgeless: The German scientist.
* AllGermansAreNazis
* ArtisticLicenseChemistry:
** Creating the seahorse signature is quite implausible with today's technology, and was certainly impossible in 1943.
*** The idea is that the German scientist spent the last 70 years or so developing the toxin, and made it as his twisted fuck you to Walter's dad. Even without that, considering Massive Dynamic, Walter and ZFT, making a chemical weapon with a carbon structure that looks like a seahorse is the least improbable thing.
* ArtisticLicenseHistory
** DNA was actually discovered Swiss physician Friedrich Miescher in 1869, well before Nazi Germany.
*** The theory of DNA containing a cell's genetic information, however, was first proposed by Oswald Avery in 1944 and was generally accepted only after Francis' and Crick's discovery of the now-famous double-helix structure (with its implications for DNA's duplication mechanism) in 1953. So a Nazi scientist doing DNA-based genetics would indeed have been ahead of his time.
** Peter thought his grandfather immigrated in 1933, which he described as "long before the Nazis ever took power", but in actuality the rule of the Third Reich and Adolf Hitler in UsefulNotes/NaziGermany started in 1933.
*** "Long before" could simply mean months before.
* ArtisticLicenseMedicine:
** Someone poisoned by cyanide actually has cherry red blood, not blue blood.
* BitterAlmonds: Averted.
* CarryingACake: Averted, the three layer wedding cake being carried in the opening scene is never shown again.
* CoolOldLady: Eva Staller. From what little we saw of her, she was nice and cool for someone who survived the holocaust. And she was about to bust the German scientist right before she choked to death (In RealLife, one woman who did recognize UsefulNotes/JosefMengele in a crowd after WWII fainted, so it's a testament to how cool ''this'' old lady is).
* DrivesLikeCrazy: Walter
* HoistByHisOwnPetard/KarmicDeath: Hoffman gets killed by his own chemical weapon by Walter, the son of the guy who worked against him, after he tried using the chemical weapon on Walter himself.
* LegoGenetics: Most of the features described by Walter, like height and weight, are a polygenic trait that also can be strongly influenced by environmental factors.
*** But that doesn't mean the chemical weapon couldn't be used to target people with a genetic predisposition to being thin or fat.
* MasterRace
* NerdyInhaler
* PoliticallyIncorrectVillain: Hoffman who created a chemical weapon that targets people according to pre-programmed genetic traits, and he tests at the wedding of one of his Jewish victims. His next plan was to unleash it on a human rights conference, where he and anyone else who was blonde and blue eyed would be the only ones left standing. Needless to say, it's satisfying when Walter kills him with his own weapon.
* SinsOfOurFathers
* StupidJetpackHitler
* TrueArtIsIncomprehensible: In Universe the basement artist who thinks making cut-and-paste artwork of the Nazis is a way of depicting them negatively. And if that isn't bad enough, he used Peter's grandfather's science books to do a Hitler caricature.
--> Eric Franko: I'm not a Nazi. I'm an artist. It's about the banality of evil, uh, like the Nuremberg trials showing history's tyrants as these regular schmucks. (...) Sadly, the, uh, contemporary art scene has yet to, um -- fully recognize my particular contributions.