At a church in rural Montana, a preacher (Clint Eastwood) is conducting a Sunday service when some men come in and start shooting at him. He escapes, with the aid of Lightfoot (Jeff Bridges), a car thief who happens to be driving by and helps him by running over one of his pursuers and giving him a lift.
Lightfoot discovers that the preacher is really one of the members of a gang who robbed a security company a few years ago and were never caught, and that he had the nickname "Thunderbolt". After the two of them stop for ice cream, after they get back, the two remaining men chasing them the vicious Red Leary (George Kennedy) and the Gentle Giant Eddie Goody (Geoffrey Lewis) catch up, and they want the money from the robbery. Thunderbolt explains that the money was in a one-room schoolhouse, but the building has disappeared and the other member of the team who knew about it is dead. Lightfoot has a suggestion: pull the same robbery of the same company over again, because nobody will be expecting it.
The four of them plan out the robbery, including timing the police for how long they'd get there, getting the outer safe combination from the security company manager, preventing the telegraph operator from being able to warn the police when the silent alarm rings there, then two of them sneaking into a drive-in next door to the security company by hiding in the trunk along with the money after they rob the security company, while just Thunderbolt and Lightfoot (dressed as a woman) apparently ride into the theatre.
The police show up shortly after the robbery, and because Red sneezes and a shirt was showing from the trunk of the car, the drive-in cashier figures they were sneaking people into the theatre and the police are directed to them. They escape, but in the process Goody (in the trunk) is shot by the police. Red dumps the dying man out, crawls into the passenger area through the back seat hatch, and takes over the car at gunpoint. He pistol-whips the other men and kicks Lightfoot in the head because he doesn't like him, and drives away...straight into a police roadblock. They shoot him, he crashes into the department store where he worked as a cover and is mauled by the junkyard dogs the store has in the building overnight to keep out burglars.
Thunderbolt and Lightfoot hitchhike out of town, then discover a one-room schoolhouse. The building had been moved, intact, a year earlier. They take the blackboard off the wall, and find the money from the original robbery, just as it had been hidden. Cut to a scene where Thunderbolt is driving out of a dealer with a brand new Cadillac convertible, picks up Lightfoot, and they drive off to see what's over the next mountain...
...only the beating Lightfoot took from Red caused some sort of brain trauma, and he collapses into the passenger seat, dead. Thunderbolt, even though he got away with the money, is unhappy at the death of his friend as he continues driving down the road.
While only a moderate box office success, this 1974 action-comedy film was critically adored, and allowed its writer/director Michael Cimino the clout to make his next movie, The Deer Hunter. Jeff Bridges was nominated for an Academy Award for Best Supporting Actor for his role; Eastwood's performance was also highly praised, and he believed he also deserved an Oscar nom, though none came. Clint blamed the relative failure of this film (compared to his other pictures of the time) on United Artists' poor marketing. Though this was meant to be the first in a multi-picture deal with the company, Eastwood soon went back to Warner Bros. and never made another film for UA.
- As the Good Book Says...: Isaiah 11:6 - "And the wolf shall dwell with the lamb, and the leopard shall lie down with the kid."
- Badass Preacher: Thunderbolt, until his "friends" find him and start shooting.
- BFG: How Thunderbolt got his name - he used a 20mm cannon to blast open a vault. In the movie, he does it again.
- Chekhov's Gun: Red mentions having allergies early on, and it's a sneeze from him that gives him and Goody away to the drive-in movie cashier when they hide in the trunk.
- Defensive Failure: Even with his guns drawn and Thunderbolt beating up his partner Red, Goody still won't shoot him. It makes sense since previously they had been part of the same criminal gang.
- Definitely Just a Cold: After being kicked in the head repeatedly by Red, Lightfoot experiences numbness on his left side, dizziness, and briefly loses consciousness. As his symptoms worsen, he shrugs it off with a smile and insists "I must be tired or something..."
- Deus ex Machina: Played with. After Red gets caught with the money, Thunderbolt and Lightfoot hitch-hike, coincidentally arriving right at the schoolhouse Thunderbolt left the original $500,000 in years ago, the schoolhouse having been relocated. Inside, they find the money. Not that this helps Lightfoot.
- Disguised in Drag: Lightfoot wears a wig and dress to gain access to and ultimately incapacitate the Western Union security guard in charge of monitoring the alarm. Later on, he pretends to be Thunderbolt's date to the drive-in.
- Downer Ending: OK, sure, Thunderbolt has the missing money back, but Lightfoot dies as they drive down the road celebrating.
- Drive-In Theater: How they plan to hide out when the police are next door at the security company checking out the robbery. Unfortunately, somebody sneezed.
- Interrupted Intimacy: While Thunderbolt secures the manager and his wife and gets the combination to the safe, Red finds the manager's daughter and her boyfriend in flagrante and leers a bit before tying them up. Later on, the manager and wife (still tied together) manage to hop to their daughter's room to make sure she's safe and find the two teenagers naked, Bound and Gagged, and face-to-face on the bed.
- Money Grinding: The crooks have to take temporary jobs to make ends meet while they case their target, and to earn enough money for the equipment they'll need for the second robbery. Thunderbolt works in a metal shop, Lightfoot does construction labor (where he gets a free show from a female client while putting in a sprinkler system), Red works as a janitor in a department store, and Goody drives an ice cream truck.
- Noodle Incident: How Thunderbolt won the Silver Star in Korea.
- Only Known by Their Nickname: The two titular characters never have their real names told on-screen.
- Punk in the Trunk: How two of them are hiding when going to the drive-in.
- Robbing the Dead: Between being abandoned by Red and picked up as a hitchhiker, Lightfoot replaced the dress with the suit off of Goody's dead body.
- Reality Ensues: A pretty major beating, including several severe blows to the head, leaves Lightfoot a little dazed at first. But as time goes on his condition worsens, and he eventually dies of a brain hemorrhage.
- Twist Ending: Lightfoot's death.
- Truth in Television: A bank robbery with an anti-tank rifle sounds far-fetched. But it really did happen on October 24, 1965, when Joel Singer shot his way in the vault of the Syracuse, New York branch of the Brinks company, earning him $433,580 in cash and a place on the FBI's Most Wanted list.
- Wacky Wayside Tribe: While escaping from Red and Goody at the beginning, Thunderbolt and Lightfoot are picked by a driver that has a raccoon and several rabbits on his car, Drives Like Crazy, is The Unintelligible, and that gets hostile with the two when he stops to do some impromptu rabbit shooting with a shotgun. It's implied that the man was acting crazy because of his car releasing exhaust fumes into the driver's area.