Luther John Stickell joined the Impossible Mission Force (I.M.F.) at an unknown time (knowingly before Ethan) and was the force's computer specialist. Luther would later become an disavowed agent and went into the shadows against his former employers.
After Ethan Hunt learned there was a mole in the IMF and the NOC list was faked, he needed a team of operatives off the grid to clear his name. Hunt enlisted disavowed agents Luther and pilot Franz Krieger alongside Jim's wife Claire.
Stickell is chosen as "Cyber-Ops" for his reputation as a well-known hacker and phreaker. Reluctant at first, Luther is baited into the hack when Ethan played to Stickell's ego, selling the job proposal as "The Mount Everest of hacks". Posing as a team of firefighters putting out a small blaze within the building, the rogue IMF group breaches the CIA and infiltrates the main computer mainframe via a remote computer terminal at CIA Headquarters at Langley, Virginia. In order to gain access to the floor with the NOC List, Luther hacks into the building's computer-controlled electrical system, triggering the fire alarm on that floor.
Because of his agility, Hunt performs the physical act of obtaining the information himself but has Luther, in his ear via headset, instructing him on performing the hack. Luther, from the team's stolen firetruck parked outside the building, obtains the password to the terminal by hacking into the CIA's online network from a laptop. After obtaining the list, Hunt discovers that his team leader Jim Phelps not only survived the initial mission in Prague, but also suspected that he is the real mole and the man responsible for framing him, despite Jim's insistence that CIA Director Kittridge was the mole.
After learning this from Ethan, Luther helps him double-cross Claire and Jim together. Aboard a train headed for Paris, the arms dealer called Max (Ethan's buyer of the NOC List) and her bodyguard are caught with the stolen data, the CIA drops their case against Hunt and reinstates him, along with Luther. When Ethan and Luther celebrate together at a British pub, Luther proclaims he's "The Flavor of the Month", indicating that the CIA is now treating him like royalty thanks to his help. At the same time, he muses that he's "gonna miss being disreputable" as he is no longer in hiding and incapable of the illegal computer activities he was privy to performing before he was reinstated. Before going their separate ways, Hunt smiles and tells Luther that, if it makes him feel any better, he will always see Luther in that light.