The 39 Clues Wiki
The 39 Clues Wiki


Mission Titanic is the first book in Doublecross, the fourth series in The 39 Clues. The book was written by Jude Watson and was published on February 24, 2015.

Official Synopsis[]


At only seventeen years old, Ian Kabra is head of the Cahills, the most powerful family in the world. He has presidents on speed dial, generals at his beck and call. Ian knows he’s an ideal leader and the only man enough for the job.

There’s just one small problem: He’s already messed up big-time. A Cahill from the past calling himself the Outcast has risen to challenge Ian with an impossible test. Ian was thrown out of his post and the Outcast took over the mansion. The Outcast has re-created four of history’s greatest disasters and dared Ian to stop him. If Ian and his allies can’t decipher the Outcast’s hints in time, innocent people will die. Ian’s only chance to beat the Outcast is to track down his former allies, Amy and Dan.

But finding Amy and Dan will demand from Ian an impossible sacrifice...


In Attleboro, Cahill family leader Ian Kabra is being fitted for a new suit in preparation for the Cahill Family Summit the next week. Ian's second-in-command, Cara Pierce, bursts into the room and informs him that the Summit had been moved up a week on Ian's calendar and that she cannot access the Cahill satellite, Gideon. Cara then attacks Ian's tailor, Mr. Funicello, who had been trying to sedate Ian. Mr. Berman informs Ian that several Cahills have arrived at Cahill Manor, but, when Ian goes out to address them, he is attacked by Saladin, destroying his pants.

Around the world, several Madrigal agents receive an emergency alert on their phones. Nellie Gomez disappears from a cooking competition in New York City, while Jonah Wizard and Hamilton Holt leave a movie premiere in Paris.

Ian prepares to give a speech to the assembled Cahill leaders (including his father, Vikram, via video call), but the power goes out, and an old man, calling himself the Outcast, appears onscreen. The Outcast rails against the leadership of Ian and of Amy and Dan Cahill, the winners of the Clue Hunt, and proposes a test to determine the new family leader. He says that he will replicate four disasters and reads a poem hinting at the first disaster. Tomas leader Magnus Hansen leads a coup, throwing Ian and Cara out of the house.

Later that day, Hamilton interrupts Amy and Dan, who are in exile from Cahill activity, while the siblings are BASE jumping in France near the Swiss Alps. Ian, Cara, Hamilton, and Jonah inform the Cahills about the Outcast's threat. After researching the poem, the group concludes that the Outcast intends to recreate the destruction of the Mont-Blanc and sets a flight plan for Halifax.

Back at Cahill Manor, the Outcast meets with his five conspirators: Magnus, Ekaterina leader Patricia Oh, Janus architect Toby Griffon, Lucian billionaire Melinda Toth, and Zen assassin Alek Spasky, also a Lucian. The Cahills discuss their plan, and tensions boil over, leading to a confrontation between Patricia and Alek.

In Mexico, Nellie and Sammy Mourad track down Fiske Cahill, who is dancing at a festival as the masked dancer El Coyote. He describes the history of Cahill Outcasts: a title used by Grace to throw people out of the Cahill family, including Fiske himself. He recommends that they visit Beatrice Cahill in order to learn more about the Outcast's background.

The team in Halifax uses Jonah's fame to distract the Port Authority long enough for Cara to hack into their systems and find the day's shipping details. The team splits up to search the ships, and Amy realizes that the Outcast may be using a ship as a bomb. A bit of computer work by Cara reveals that the captain of one of the ships in the Halifax port, the Aurora, once worked for James Atlas, an international weapons dealer, and Cara sets up a meeting with him. The Cahills meet Atlas at St. Paul's Church, and Ian convinces him to take Amy, Dan, Hamilton, and himself aboard the Aurora. Atlas takes them onto a cabin cruiser and pilots the boat into the open ocean, but then cuts the engine and pulls a gun on the Cahills.

Nellie, Sammy, and Fiske videocall Beatrice, who is packing for a vacation. During the call, Beatrice reveals Grace's long history of making Outcasts, which included Beatrice's ex-husband Stephano Breglio and Grace's husband Nathaniel Hartford, who Beatrice claims Grace arranged to be assassinated in Moscow. Nellie and Sammy then book a flight to Singapore, where they meet Tiffany and James Chen and their daughter Mabel. Mabel tells them about another Ekat, Bee Arnold, who had recently moved to Singapore but lived as an outsider. When Nellie and Sammy arrive at her address, they discover that Bee Arnold is former Cahill traitor Sinead Starling, who is living in Singapore with her brothers Ned and Ted. Sinead reveals that Patricia had been in Singapore recently and attempted to recruit her to her side, and she warns Nellie to be careful.

On Atlas's boat, the Cahills take advantage of a wave to take his gun and escape his ship. Jonah leverages his new relationship with the head of the Port Authority, Bill Hannigan, to search the Aurora. They discover illegal weapons, but no explosives, and a comment by Hannigan causes the Cahills to realize that the Outcast's poem was referring to the Titanic, not the Mont Blanc, and Jonah discovers that a replica, the Titanic II, is set to begin its maiden voyage the next day.

The group arrives in Ushuaia, Argentina to board the Titanic II, built by billionaire Peter Zimmer. Jonah attempts to leverage connections to get a cabin on the cabin, but is denied, and Ian steals the identity of a scientist, Rollo Hardcastle, to sneak aboard, along with Amy, Dan, and Hamilton.

Nellie and Sammy are followed and threatened by mysterious men in Singapore, who tell them to go back to the United States. Mabel, who had broken into her father's computer, theorizes that her parents are in league with the Outcasts and reveals that Patricia Oh had sent research stolen from Sammy's father, Darsh Mourad, to James Chen.

Onboard the Titanic II, Dan attempts to steal a staff card key. He fails, but meets an Ekaterina Antarctic scientist, Dr. Jeff Tagamayer, who recognizes Dan and offers to help. Ian overhears a conversation between Alek Spasky and another crew member, and learns that Dr. Jeff had only lasted at his research station at the South Pole for a month (when he had claimed it was a year), and that he was being escorted to Deception Island. He orders Cara to investigate the scientist.

Back in Singapore, Nellie and Sammy break into the Chen computer and find Darsh Mourad's lab notes, indicating the discovery of combustibility of the biofuels used on the Titanic II. The notes are also initialed by Rollo Hardcastle and another researcher, JET. The pair are forced to hide, but relay that information to Jonah. In Ushuaia, Jonah and Cara pass the information on to Ian and the others, and discover Rollo's corpse in his room, killed by the same weapon that Nellie and Sammy had been threatened with.

Amy, Dan, and Hamilton follow Dr. Jeff onto Deception Island. They realize that he is the JET mentioned earlier, and Dr. Jeff reveals his allegiance to the Outcast. He locks the other Cahills in a research station on Deception Island and escapes on a helicopter. The trio escapes by collapsing the station's stilts and meet up with Ian on the beach with less than half an hour before the Outcast's deadline to stop the explosion. The Cahills' boat is attacked by Alek Spasky, who uses the spears used to kill Rollo Hardcastle, and they reboard the Titanic II ten minutes before the explosion. The group rushes to the engine room and pours oil into the engine, relieving the pressure and preventing the explosion.

Jonah receives a last text message from Nellie, pointing them to Mabel and asking him to save Amy and Dan. Meanwhile, back at Cahill Manor, the Outcast opens a hidden safe in the library and retrieves several documents.


Historical figures mentioned[]


  • The first book of a new series that doesn't have a prologue in the entire series.
  • Like the second series, Cahills vs. Vespers, the color of the first book is not the same as the color of the series logo.
  • This is the second 39 Clues book to feature a ship on the cover, the first being Storm Warning.
  • First book to have digitized cards in the hardcover version of the books.​​​​​​


  • Book Cover Puzzle - (Hidden Words) - Disaster is in the air. This pertains to the next disaster that the Outcast will be replicating, Hindenburg. (Hidden Words) - Elec. Crane ; Boiler uptake casing. (Hidden Numbers) - 10 ; 53 ; 9 ; No. 13334.
  • Ship Page Puzzle - ​(Morse Code) -​​ Moscow​​​
  • 39+ Pages Puzzle -​ (Morse Code) -​​ Beatrice is key​​​
  • End Page Puzzle - ​(Morse Code) -​​ Ekats rule, the others drool


The following cards will only be available as digital cards:

Card 335: Al Capone

Card 336: Outcast Warning

Card 337: Acquired Taste

Card 338: Pranav Kabra

Card 339: Ian Kabra

Card 340: Titanic - the back of the card is a part of The Outcast Master Plan Puzzle


Mission Titanic - artwork