‘The Americans’ recap: Even the KGB is scared by a super-deadly bioweapon

The Cold War is raging and the USSR needs an ace in the hole in case the U.S. launches a preemptive nuclear strike. And that “ace” deployed in a Soviet counterattack could be a weaponized version of the Lassa virus.

The hemorrhagic fever produced by this virus is so horrifying, however, that even KGB agents are filled with dread on “A Roy Rogers in Franconia,” Season 4’s penultimate episode of “The Americans” on FX.

“Lassa fever is a very undignified way to go,” points out William Crandall (Dylan Baker), a longtime Soviet “mole” employed by the U.S. Army’s biological defense program at Ft. Detrick.

“Undignified” is an extreme understatement.

“You basically dissolve inside,” William explains to KGB officer Philip Jennings (Matthew Rhys). Then liquefied organs pass out of your body with a terrible whooshing sound.

“I can’t do this one,” admits William, who’s under orders from Moscow to infiltrate the Army’s most-secure lab and steal a modified strain of the virus.

“This is one of the deadliest pathogens on the planet,” William stresses. “Just say it actually gets out there. I play a part in that.”

Since William refuses to proceed, KGB handler Gabriel (Frank Langella) must intervene. Complete this one last assignment, Gabriel urges, and William can return to the USSR as a hero.

At the Soviet Rezidentura in Washington, meanwhile, KGB officer Oleg Burov (Costa Ronin) becomes increasingly concerned about the Cold War’s direction after speaking with his comrade/lover Tatiana Evgenyevna (Vera Cherny).

Tatiana’s work with William on acquiring the bioweapon just earned her a promotion to the KGB’s top post in Kenya. But she worries that the Lassa virus might slaughter “half the people on the Eastern Seaboard.”

This startling revelation prompts Oleg to rendezvous with his frenemy, Agent Stan Beeman (Noah Emmerich) of FBI counterintelligence.

Oleg fears that Soviet scientists would misuse the virus. So he gives Stan just enough information to figure out that William is the undercover agent.

The magnitude of this discovery sidelines a smaller FBI operation involving the office mail robot.

Agent Dennis Aderholt (Brandon J. Dirden) finds a KGB recording device hidden inside the robot, which leads to the arrest of a female janitor (Ozzie Stewart). She was being paid to swap out the tape each week and give it to a KGB operative she met at a Roy Rogers restaurant in Franconia, Va.

Agent Wolfe (Peter Jacobson), the new counterintelligence supervisor, had intended to nab the Soviet operative right way. But now Wolfe backs off to focus on William and avoid alarming KGB officials.

Finally, teenager Paige Jennings (Holly Taylor) is deeply shaken after her spy mom Elizabeth (Keri Russell) kills a would-be rapist during a street attack. Witnessing her mother’s martial arts expertise makes Paige realize her parents lead far more dangerous lives than they let on.

When Philip leaves late at night on a mysterious assignment, Paige accuses Mom and Dad of lying because they won’t discuss their clandestine activities in detail.

“We’re not lying to you,” Elizabeth insists. “But you don’t need to know everything.”

“You just killed a man in front of me,” Paige retorts. “I might as well know everything. Do you trust me or not?”

Does this mean Paige is becoming a junior KGB agent? She is gathering intel on their neighbor Stan, who shares FBI news with his son Matthew (Danny Flaherty). And could Paige be seducing Matthew with a gentle kiss?

“You want to be Matthew’s friend, be Matthew’s friend,” Philip emphasizes. “But don’t do anything because of us.”

Elizabeth probably has a different opinion, however.

And Paige? Too early to tell.