The AH.commers are relaxing on a Caribbean holiday resort in a peaceful timeline, when they are virus-bombed and the planet's inhabitants start to turn into national stereotypes - it's the Stereotypica Virus. Annoyed due to their vacation being ruined, the AH.commers track down the virus to a 'hairy plane' (the Hairplane) and also note that there's a familiar ship, the German ship from "DON'T MENTION THE PORN!", in orbit. They pursue the Germans through several TLs, including passing up a planetful of women whose men all died from a plague and urgently need impregnating.
Eventually they reach Deutscherwelt, the Germans' homeworld. It transpires that, far from being the creators of the virus, the Germans' mission is to hunt down the creators. The virus is what causes them to speak so stereotypically, and it mutated when it attacked their world - Steffen and co. were the first to be infected, and the mutant virus turned everyone else into Germans too. Doctor What speaks with the Weltstag, and agrees to help hunt down the Hairplane. GBW and luakel discuss Flocculencio's past, and his obsession with the two traitors to Goatism, Nekromans and Justin Pickard.
The two ships exchange hostages, Alayta and Michael, and Thande, Torqumada, the Mosquito and Bobo all go to the infected Caribbean world to try and cure it. Torqumada discovers that the virus mutates with every release, and even the AH.commers' own immunity will break down after long contact with the infected. We then learn that Landshark has been playing Twister with Alayta…
Doctor What's information and the AH.com Ship's sensor data of the Hairplane help narrow down the possible future attack sites, and they identify the planet of The King (“THE RETURN OF THE KING”) as the most likely one. The two ships shift there, Dave Howery installing 'Blue Schvädeschuz' armour to help resist the Hairplane's technobabblyon particle weapons. It emerges that the King has gone off living by himself, and in his absence the planet has broken down into rival religious factions each claiming to be the true followers of the King. The AH.commers beam down and persuade the King to come back; he immediately whips the people into shape and organises a defence of the timeline.
The Hairplane attacks. An AH.com/German boarding party goes over in the middle of the battle and learns that the ship is run by Justin Pickard, hence the hair, and crewed by bald goons who serve him in exchange for a promised cure. Flocculencio goes berserk and Nekromans is captured. The AH.com and German ships don't quite manage to stop the Hairplane, but they damage and delay it enough that the King's fighter planes are able to blast the bomb bay doors shut and the Hairplane is forced to retreat to the Hub for repairs.
Doctor What thanks the King, who muses that he won't always be there to save his people. The AH.com and German ships make repairs, and Susano complains how the Hub's neutrality policy means that they can't attack the Hairplane there. But Doc has another idea - he gets Kit to talk to Fellatio Nelson about it…
The loss of Nekromans means Pickard promotes Ran Exilis to “Hirsuite Prime” (a parody of Goa'uld First Primes) and orders the recruitment of a new crewman. After an assemblage of unsuitable trolls are rejected, a disappointed Exilis is ambushed by AH.commers and Germans disguised as thugs, but is rescued by a tall bald figure who appears to be a bald Fellatio Nelson. Pickard takes him on as the new crewman, but Nelson' competence soon makes Exilis jealous of him.
Meanwhile, on the Caribbean planet, Thande and Torq succumb to the virus, but the Mosquito inadvertently completes their cure. Personified as Thermopylae, the cure removes the virus from the planet, but warns that without data on the virus, they won't be able to make a general cure.
On Nelson's advice, the Hairplane attacks the “IT CAME FROM HOLLYWOOD” planet. Of course the AH.commers and Germans already know where they're going. They ambush the Hairplane and Flocculencio, Steffen and Susano beam over, uploading information about the virus from the Hairplane's databanks to the AH.com, though Leo has to overwrite his navicomp data to do so. Pickard interrupts them halfway through and almost stops the data transfer, but Steffen heroically attacks him - and is killed by Pickard. Flocc and Susano are almost defeated as well, but Flocc uses his S(a)tanic Appletini with Susano's cigarette lighter to make a Molotov cocktail, which sets Pickard's hair on fire. The Hairplane, damaged by the space battle, crashes through the atmosphere. The AH.com ship goes into a power dive to get within teleporter range, and rescues the two survivors, along with Steffen's body and the surviving bald goons.
At the same time, Nekromans breaks out of prison - strangely able to predict luakel's fighting moves - and escapes down to the planet in an escape pod. He witnesses the Hairplane crash into Mount Rushmore, killing Pickard, and is distraught.
On the AH.com Ship, Thande and Torq make up a general cure from the Hairplane data and cure the Germans. We learn that the bald Fellatio Nelson was actually his genuinely bald twin, The Bald Imposter - but only after Kit had tried to 'comfort' him. Steffen is buried on the 'Hollywood' planet in great ceremony. They shift back to the Deutscherwelt timeline and cure the world, but everyone slips straight back into the WW2 that was ongoing when the virus hit, and Susano and co. are banished from the planet. They resolve to stay in touch with the AH.commers.
At the end, Doc asks for the coordinates of the women-only planet they found earlier, and Leo tells him that he had to overwrite that data with the Hairplane virus data. The AH.commers' scream is audible by Ian, as far away as the Hub. And, although the AH.commers don't know it yet, the planet has instead been found by the first shift-capable ship of the Lesbian Space Marines from “LESBIANS OF DOOM”…
The story features continuity from a number of other episodes -
The Stereotypica Virus was first seen in “HOW SHARPER THAN A UNICORN’S HORN”
The King was met for the first time in “THE RETURN OF THE KING”
The Hollywood Monster Planet was visited in “IT CAME FROM HOLLYWOOD”
The Germans were introduced in “DON'T MENTION THE PORN!”
And the Lesbian Space Marines made their appearance for the first time in “LESBIANS OF DOOM”
Thande first worked out the basic concept as early as 2006 - then, he had Pisces74 (a recently joined member, who then unexpectedly left) as the virus villain, a swarm of 74 superintelligent psychic fish in a tank with a human minion.
The Germans were then added to that concept - at once point Deutscherwelt was going to be an ASB timeline made up entirely of tesselated Germanies, but instead the virus link was included.