The 39 Clues Wiki
The 39 Clues Wiki

Outbreak is a standalone book in the 39 Clues series, Superspecial. Written by C. Alexander London, it was released on September 27th 2016.


CALLING ALL CAHILLS! Announcing a 39 Clues Superspecial adventure -- the gang is back, and called to investigate one of their own: Sinead Starling.


The Cahills are the most powerful family has ever known. For the past five centuries, they have secretly served as guardians of the world. The Cahills command presidents, take down corrupt governments . . . and are currently led by a fourteen-year-old boy with a superhero complex.

Dan Cahill may be young, but he's nobody's fool. So he knows he must act fast when he learns that Sinead Starling, a former friend who betrayed the family, is up to her eyeballs in a plot to control a deadly virus. But is Sinead behind the plot, or is she a hero trying to stop the virus from getting out? The search for Sinead will take Dan and his friends from Cuba to the Bermuda Triangle, where the fate of the world may just depend on whether the Cahills can trust a traitor.

Sneak Peek[]

Boston, MA

Dan ​Cahill knew a thing or two about collectors. When he was younger, he had collected baseball cards, autographs of famous outlaws, Civil War weapons, rare coins, and charcoal rubbings of people’s tombstones.

For a while he had even collected casts, but he had broken bones that the size and smell of that particular collection had become, to quote his big sister, Amy, "disturbing." However the collector he was tracking through the streets of Boston was a different sort of collector entirely. Dan collected stuff he could geek on - meteor fragments, memorabilia from obscure sports, creepy photos he found at flea markets. The guy he had his eye on collected stuff he could sell for millions of dollars, stuff that was stolen from archaeology sites around the world and smuggled away from the countries to which they belonged: Buddhist relics from Cambodia, statues from Iran, religious carvings from Egypt. The artifacts were priceless, sacred, and irreplaceable. They should've been in museums or left in the temples or tombs where they'd been found. They were the sort of things that someone might kill for. . . . .


Amy, Dan, Ian, Jonah, Cara and Hamilton are chasing a collector who happens to have stolen a historical silver star. They engage with a private detective who so happens to want to sell the silver star. When they go back into the mansion in Attleboro, they are visited by two CIA agents, Agent Pratt and Agent Gimler. The agents show the Cahills an image of Sinead stealing a genetically modified version of goat pox, one that affects humans. The Cahills then accept the job the CIA agents have for them, to capture Sinead and stop an outbreak, hence the title Outbreak. One team, Cara, Ian, Hamilton and Jonah go to Sinead's previous house. The other, to Havana, Cuba to find both Sinead and Dr. Miller, the creator of the modified goat pox.

Team one is in Sinead's old base or lab when a bunch of people bust in with hazmat suits and weapons. Things take a turn for the worst when they accidentally get infected with the modified goat pox.

Then, the story cuts to Sinead Starling, who is still in Havana. It is revealed here that Sinead would do something to cure the Outbreak herself, as she wanted to redeem herself. After that, she goes to the promenade to dance and breathe the fresh air off the ocean. The people around her were dancing, so she decided to do the same to avoid suspicion. Then, she inconspicuously dropped a vial containing the modified goat pox onto the sand. She then covered her nose and mouth and stepped on it, crushing it.

Team two was in Havana where they finally located Dr. Nueman's apartment. An ex-Cahill who had fled to Cuba on their side instead of siding with Grace in America during the Cuban Revolution. His daughter greeted them, telling them that Dr. Nueman was busy attending to patients. They then left to go to Hermanos Ameijeiras Hospital. They find out from the doctor that the modified goat pox was modeled after a seventeenth-century Italian disease known as tarantism. They also learn that the goat pox is a baculovirus modified to infect humans. They find out that Dr. Miller is in Old Havana. what happens...why do they have to murder saladin??

Then, the story goes to Attleboro with Nellie going back to the mansion, where she was alone with Saladin. Then, she switches on a monitor when she finds out that someone was trying to break in into the mansion. However, all she saw was the front gate opened. Then, she panned the camera which then shows Ian's car. Team one had returned, but they were all infected with the modified goat pox, and they were all dancing.


Historical Cahills mentioned[]


  • This will be C Alexander London's 2nd book, making him the first author not in The Clue Hunt to write multiple books.
  • While previous 1st books in series had gaps of more than six months after the end of the previous series, this book came out only 3 months after its predecessor, Mission Atomic.
  • It is the fifth book in the series to have a single word title.
  • It is also the only book in the entire series to be for $13.99. All other main books have been for $12.99 in the US.
  • It has also been confirmed by Admin Sheila, that Outbreak will not have a Mission corresponding to it.


  • Book Cover Puzzle - ​(inverted) - ​Havana
  • Test Tube Page Puzzle - ​(inverted) - ​The cat can destroy the world
  • 39+ Pages Puzzle - ​(inverted) - ​Saladin rules
  • ​End Page Puzzle


Currently unknown if this will have cards. But since it doesn't have any mission nor the "Collect the Cards" in the cover, it might not have one.