Azazel is a demonic spirit and the main antagonist of the 1998 neo-noir supernatural thriller movie Fallen.
Philadelphia Police Detective John Hobbes in a snowy forest, narrates of how he "almost died." In the present day, Hobbes gains notoriety for capturing serial killer Edgar Reese. After Reese is executed, Hobbes and his partner Jonesy investigate a string of murders by an apparent copycat killer. Eventually Hobbes tracks down the killer and confronts him alone, where the man makes a startling claim: he is the same killer Hobbes sentenced to death, but not Edgar Reese; rather, he is the demon Azazel, and was possessing Reese's body during the murders. Before Reese died, he vowed to get revenge on Hobbes, his friends, and family.
Azazel claims he can possess any person merely by touching them. One of the few exceptions is Detective Hobbes, which has turned Azazel's ire at the Detective for capturing him into an obsession. Hobbes is skeptical of Azazel's claims until the demon begins to sing "Time Is on My Side", then begins to possess people via touch, continuing to sing the song as he moves from body to body before fading away into the crowd of people on the street. Hobbes realizes that Azazel can be drawn out by speaking Syrian-Aramaic, a language that has been around for thousands of years, which is the only way to find out who is possessed and who is not.
Hobbes follows a lead from a riddle Azazel gave him concerning Robert Milano, a decorated cop who committed suicide in his mountain cabin 30 years earlier. Hobbes locates Milano's daughter, Gretta, who explains that her father was framed for corruption and killed himself to avoid his eventual conviction. When Hobbes journeys to the cabin, he finds a clue uncovering a deeper truth: when he died Milano was trying to kill Azazel. Hobbes begins to realize that Azazel wants the Apocalypse to start as soon as possible.
To provoke Hobbes, Azazel possesses his nephew Sam and attacks John's intellectually disabled brother Art in their home. He flees into other people on the street, ending up in a schoolteacher. As the teacher, Azazel draws a gun and forces Hobbes to shoot his host in front of a group of bystanders. Hobbes comes to realize that Azazel can transfer from body to body upon his host's death and inhabit anyone—including Hobbes.
Lieutenant Stanton informs Hobbes that his fingerprints were found at one of the murder scenes and along with the bizarre circumstances of the shooting of the teacher Azazel possessed, he has become a suspect for all the murders. Azazel inhabits several of the witnesses and gives false accounts that the shooting was unprovoked, thereby throwing further suspicion on Hobbes, framing him for the crime.
Azazel sneaks into Hobbes' home overnight by possessing his brother Art to make him commit suicide by injecting himself with poison. Hobbes and Sam decide to go on the run. The next day, Hobbes takes Sam to Gretta's where they consult several ancient texts and discover that Azazel's ability to transfer from body to body in spirit form has a finite range of about one-sixth of a mile and must be performed within a relatively short time period. Hobbes then leaves Sam with Gretta and drives alone to Milano's remote cabin to isolate and trap Azazel.
A short while later, Lieutenant Stanton and Jonesy arrive to take Hobbes into custody, but Jonesy wants to make Hobbes disappear, and make it look like he committed suicide by driving his car into a lake. Stanton becomes infuriated by this assumption, and forces Hobbes to drop his gun. Jonesy suddenly shoots Stanton, revealing himself to be possessed by Azazel, and then chases Hobbes into the cabin. Azazel tells Hobbes that he will continue to kill more people, then move on to another person. They fight for control of the gun, during which Jonesy is mortally wounded.
As Jonesy slowly expires, Hobbes smokes a poison-laced cigarette and taunts Azazel with the fact that he will soon be dead and his body will be useless as a host, thus trapping and killing him. Hobbes kills Jonesy by shooting him in the head, but Azazel then possesses Hobbes. He frantically tries to find a new host but succumbs to the poison in Hobbes' system. Azazel survives, however, by possessing a cat nearby. Throughout the film, the overdubbed narration of Hobbes' voice sometimes interjects, often explaining certain situations, almost in a noir-like style.
In the very last scene, when the cat comes out of the cabin, the narrator is revealed to be Azazel himself who claims that the war against souls is far from over. And the soul is carried on, as Azazel will wait for the "Fall of Babylon", the end of civilization.