A film adaptation, starring Alex Pettyfer as Alex Rider, was released on 21 July 2006.
After the death of Ian Rider in a "car crash," Alex Rider learns some surprising secrets about his uncle's past. He finds out that he was shot dead and his car did not crash. He is recruited by MI6, the agency his uncle worked for. After vigorous training, he is sent to investigate the Stormbreaker computers, which his uncle was investigating and to spy on Herod Sayle, the owner of the Stormbreakers. Before he leaves, he is given a yo-yo which has a nylon string and is used for gripping things. He receives a Game Boy Colour which is used for contacting, scanning; etc, and a zit cream used for burning through metal. Alex also goes under the disguise of Felix Lester. He later arrives at Sayle's mansion.
Sayle shows Alex around his own headquarters, which houses a large jellyfish aquarium containing a large Portuguese Man o' War jellyfish. Alex also meets Mr. Grin, a henchman who's name derives from his time as a circus performer, catching knives with his teeth. An accident left him without a tongue and two large scars which give him the appearance of constant smiling and devilish look.
Initially the trip goes well, with Alex finding a cryptic diagram made by his Uncle Ian in the canopy of his bed. However, Sayle grows to dislike Alex. While investigating the base, Alex sees several of Sayle's agents unloading metal cases with great care from a nuclear submarine. When one of the agents drops a metal case, he is promptly shot dead by Gregorovich. Alex decides to head to the local library to do further investigation, but finds himself attacked by several armed guards on quad bikes, one of whom collides with an electric fence while the other falls from a cliff face.
While searching the library, Alex finds a map in a book about tin mining which matches the diagram left by Ian. He also learns that Ian had borrowed several books about viruses, and assumes that Sayle plans to use the Stormbreaker network to release a computer virus. Alex investigates the mine and, following the path left by his uncle, discovers a large computer manufacturing facility, where the Stormbreaker computers are being filled with a strange fluid. Alex realizes that the 'viruses' being investigated by Ian were not computer viruses, but biological weapons. Alex is detected, and nearly escapes but is eventually caught and tranquillized. When he comes to, Herod explains his plan to Alex.
When Sayle attended school, he was bullied because of his accent and skin colour. The worst bully was none other than the future Prime Minister. As a result, Sayle plans to embarrass the PM by his "April Fools Joke"; when the computers are activated by the Prime Minister, the virus, a potent strain of smallpox, will be released into every school in the country, killing the children. Sayle brags that "a spoonful of the stuff would destroy a city!".
Alex is then left handcuffed to a radiator, until Nadia Vole, an assistant of Sayle's, frees him, telling Alex that she is a fellow spy who worked with Ian Rider. However, as they head to find a mobile phone to call MI6 and inform them of Sayle's plan, she triggers a trapdoor which drops Alex into the jellyfish tank. Alex eventually gets free by using the acne cream gadget to damage the tank's supporting iron girders, causing it to burst. Vole is caught in the blast of water, and is killed by the jellyfish. Snatching up a harpoon gun, Alex rushes outside to find that Sayle's private helicopter has already left, leaving only a cargo plane on the tarmac. Using the handle of the harpoon gun, Alex knocks out a guard, taking his jeep and pistol. As he starts the jeep, several other jeeps start to pursue him as the cargo plane starts to take off. Through some fancy driving and good fortune, Alex manages to cause the destruction of the hostile jeeps. Tying the nylon cord of the yo-yo gadget to the harpoon with the yo-yo clipped to his belt, Alex shoots the harpoon which catches on the underbelly of the airborne plane. Using the gadget, he gets himself on to the plane where he confronts the pilot, who is none other than Mr. Grin. Alex instructs Mr. Grin to fly to London by threatening him with the pistol.
When they are finally over London, Alex realizes that there is not much time left before noon. He spots two parachutes and uses one to jump out of the plane. Mr. Grin turns the plane around hoping to ram into Alex. Alex pulls out the Game Boy Color and activates a smoke bomb disguised as a game called "Bomber Boy" inside the cargo plane. Unable to see, Mr. Grin loses control of the plane and fatally crashes into a dock land near the River Thames. Alex crashes through the roof of the Science Museum and dangles from his parachute which had caught on a beam. Alex draws the gun he took from a guard back at Sayle's mansion and fires blindly at the Stormbreaker computer, two shots hitting the Prime Minister and Sayle himself. Mrs. Jones saves Alex's life by ordering security not to open fire on him. MI6 immediately recalls all the computers, citing "safety issues".
Later, after a debriefing by Alan Blunt and Mrs. Jones, Alex enters a taxi. The driver is in fact Herod Sayle, who survived the bullets that Alex fired at him. He leads Alex to the top of a building where he is about to shoot Alex, but is himself shot by Yassen Gregovich, who lands in a helicopter. Alex questions Yassen about why he shot Sayle. Yassen explains that Sayle was 'embarrassing', so he had to be eliminated. Alex tells Yassen he will one day kill him, but Yassen brushes aside the comment and tells Alex to drop the spy business and become a normal schoolboy again. He then leaves in the helicopter. Just before it goes out of sight, Alex sees Yassen 'salute' him.