Ark Angel is the sixth book in the Alex Rider series written by British author Anthony Horowitz. The book was released in the United Kingdom on April 1, 2005 and in the United States on April 20, 2006.
When he comes to, he is being held hostage by Force Three, who think Alex is Paul. Alex meets Kaspar, the leader, whose head is tattooed with the world map. Kaspar explains that Nikolei Drevin, Paul's billionaire father, is an enemy of Force Three. Nikolei Drevin is funding the construction of a space hotel, Ark Angel, a threat to the environment. Alex manages to convince Kaspar he is not Paul. Kaspar decides to kill Alex anyway, setting fire to the building. Alex manages to escape off the roof by tightrope-walking from the top floor to another building. He debriefs MI6, and is released from the hospital. Nikolei Drevin calls Alex to express his gratitude, inviting him to stay at his house.
After staying at Drevin's house for a while, Alex flies to New York. At the airport, he is taken to a CIA base. Deputy chief Byrne tells Alex that Drevin is a large scale criminal. The CIA need to make sure he doesn't leave his island before he can be brought in. Alex reluctantly agrees to fly to the island; his cover is blown when head of security Magnus Payne tells Drevin that he is from MI6. Drevin tells Magnus to kill him. The next day, Alex goes wreck diving. The guard he swims with locks Alex in an old wreck to die. Tamara Knight, Drevin's employee, shows up with Alex's fake inhaler which Alex uses to free himself, and finds out Tamara is a mole.
That night, the pair tries to alert the CIA, but are caught. Drevin tells Alex that he knows of the CIA's investigation. He plans to knock the Ark Angle station out of orbit and have it impact in the greater D.C. area, destroying the Pentagon, along with any evidence against him, and most of Washington, D.C.. He tells Alex he created Force Three to make an enemy. Drevin was going to blame the destruction of Washington on them, "proving" it by having them attempt to ambush Flamingo Bay, showing their bodies as proof. When asked how he will fake it, he reveals he doesn't intend to. He has Magnus (revealed as Kaspar) kill Force Three. Alex tells Tamara of Drevin's plan, and she helps Alex escape. Alex tries to fly a power kite to Barbados. CIA men arrive on a boat, and Alex tells them about Drevin's plan as the rocket is launched.
Alex goes to Drevin's house. He finds Drevin there, about to leave, heading for his seaplane. Alex attaches two canoes to the seaplane's floats, causing it to crash. Alex is the only one able to fit into the capsule, and is sent into space to move the bomb on Ark Angel, letting it explode harmlessly. Entering the observation module, he finds Kaspar. Alex realizes that sending the bomb into space armed would have caused it to go off before reaching Ark Angel, so Kaspar had been sent with it to arm it when there. Kaspar attacks Alex, but Alex overcomes him, stabbing his head. Alex then puts the bomb in the toilet and enters an escape capsule. Ark Angel explodes as Alex returns to Earth; he lands off the east coast of Australia.