|Season 4, Episode 12|
|Air date||December 15, 2017|
|Written by||Craig Engler|
|Directed by||Dan Merchant|
|U.S. Viewers||0.61 millions|
"Return to Mercy Labs"
"The Black Rainbow"
On their quest to find the thumbprint of the President of the United States, the gang heads to Mt. Weather, Virginia, where the government has gone to wait out the apocalypse in a secret underground bunker. When they approach a vehicle with the Presidential seal on it, the person they think is the President turns out to have been eaten by his own zombified Secret Service detail; there's no thumbprint or even a hand. However, it turns out that the corpse is actually the President's husband.
The gang makes their way into the underground bunker and basically kill what's left of the zombified Congress. Finally, the gang comes across the President, who knows her husband is dead and has two remaining Secret Service agents, both named Agent Johnson. However, it turns out that the current President has no thumbs. A few days prior, Mr. Sunshine from Zona turned up, drugged the Secret Service agents, and took her thumbs. It turns out that they need the thumbs of the President from when the apocalypse started: Bill Carney. He's a zombie now and he's 25 levels down. Before the team set off to find the President, they are shown a video about Black Rainbow and learn that it's an Cold War-era fourth-strike weapon that rains down flesh-eating bacteria and rids the world of all living creatures to defend U.S. interests, even when the U.S. no longer exists.
The gang travels down to the 25th floor of the bunker, which is filled with the zombified staff of the West Wing and the cast of Hamilton. As per usual, the gang constructs a pretty serious plan: they're going to bring the zombies into an empty room and kill them one at a time until they find the one they're looking for. That’s when they realize that Warren is missing. She’s made her way further down in the zombie bunker, where she finds the President they actually need in a press briefing room, complete with a teleprompter stating that the zombie virus is under control.
With the zombie President in tow, the gang prepares to head to Washington, D.C. and Warren mentions that they'll be going to stop Black Rainbow. That’s when the current President turns on them and the Secret Service pull their guns. As Commander-in-Chief, the President tells Sarge to assist Agents Johnson and Johnson in taking Operation Bitemark prisoner. Sarge is torn, as she has grown attached to Operation Bitemark, but she’s also a Marine and she took an oath to obey her Commander-in-Chief.
Finally, the gang learns that the President is hell-bent on the Reset. She's headed to Zona and taking Sarge with her. At the last minute, Sarge realizes that the President's orders are manifestly unjust and thus illegal, and kills the President as the Secret Service agents shoot each other. 10K and Sarge take out the zombie Secret Service agents, and as Warren kills the zombie version of the President, she sees another vision of the black rainbow. She knows where to go now, Washington DC.
- Kellita Smith as Roberta
- Keith Allan as Murphy
- Russell Hodgkinson as Doc
- Nat Zang as 10K
- Gracie Gillam as Sgt. Lilley
- Ina Chang as Jane Carlson
- Micheal Daks as Mr. Sunshine
- David S. Hogan as Johnson 1
- Justin Torrence as Johnson 2
- David Natale as Male Scientist
- Jane Carlson's Husband (Confirmed Fate)
- Unnamed Members of Congress (Confirmed Fate, Zombified)
- Bill Carney (Alive)
- Johnson 1 (Alive and Zombified)
- Johnson 2 (Alive and Zombified)
- Jane Carlson (Alive and Zombified)
- "Level Z, please!" - Jane Carlson
- "We were nowhere near Mt. Weather" - the gang
- "My fellow surviving Americans...everything is fine. Phft, my ass" - Warren
- First appearance of Bill Carney (Zombified).
- First (and last) appearance of the President of the United States, Jane Carlson.
- First (and last) appearance of Johnson 1.
- First (and last) appearance of Johnson 2.