As a young ne'er-do-well named Lightfoot (Jeff Bridges) steals a car, an assassin attempts to shoot a minister delivering a sermon at his pulpit. The preacher escapes on foot. Lightfoot, who happens to be driving by, inadvertently rescues him by running over his pursuer and giving the preacher a lift.
Lightfoot eventually learns that the "minister" is really a notorious bank robber known as "The Thunderbolt" (Clint Eastwood) for his use of a 20 millimeter cannon to break into a safe. Hiding out in the guise of a clergyman following the robbery of a Montana bank, Thunderbolt is the only member of his old gang who knows where the loot is hidden.
After escaping another attempt on his life by two other men, Thunderbolt tells Lightfoot that the ones trying to kill him are members of his gang who mistakenly thought Thunderbolt had double-crossed them. He and Lightfoot journey to Warsaw, Montana to retrieve the money hidden in an old one-room schoolhouse. They discover the schoolhouse has been replaced by a brand-new school standing in its place.
Thunderbolt and Lightfoot are abducted by the men who were shooting at them—the vicious Red Leary (George Kennedy) and the gentle Eddie Goody (Geoffrey Lewis) -- and driven to a remote location where Thunderbolt and Red fight each other, after which Thunderbolt explains how he never betrayed the gang.
Lightfoot proposes another heist — robbing the same company as before — with a variation on the original plan, since Lightfoot inadvertently killed their electronics expert, Dunlap, in his rescue of the fleeing preacher. In the city where the bank is located, the men find jobs to raise money for needed equipment while they plan the heist.
The robbery begins as Thunderbolt and Red gain access to the building. Lightfoot, dressed as a woman, distracts the Western Union office's security guard, deactivates the ensuing alarm, and is picked up by Goody. Using an anti-tank cannon to breach the vault's wall, as they did in the first heist, the gang escapes with the loot. They flee in the car, with Red and Goody in the trunk, to a nearby drive-in movie in progress. Upon seeing a shirt tail protruding from the car's trunk lid, the suspicious theater manager calls the police and a chase ensues. Goody is shot and Red throws him out of the trunk onto a dirt road, where he dies.
Red then forces Thunderbolt and Lightfoot to stop the car. He pistol-whips them both, knocking them unconscious, and kicks Lightfoot violently in the head. Red takes off with the loot in the getaway car but is again pursued by police, who shoot Red several times, causing him to lose control of the car and crash through the window of a department store, where he is attacked and killed by the store's vicious watchdog.
Escaping on foot, Thunderbolt and Lightfoot hitch a ride the next morning and are dropped off near Warsaw, Montana, where they stumble upon the one-room schoolhouse - now an historical monument on the side of a highway - moved there from its original location in Warsaw after the first heist. As the two men retrieve the stolen money, Lightfoot's behavior becomes erratic as a result of the beating.
Thunderbolt buys a new Cadillac convertible with cash, something Lightfoot said he had always wanted to do, and picks up his waiting partner, who is gradually losing control of the left side of his body. As they drive away celebrating their success with cigars, Lightfoot, in obvious distress, tells Thunderbolt in a slurred voice how proud he is of their 'accomplishments', and slumps over dead.
Thunderbolt snaps his cigar in half (as there no longer is a celebration), and with his dead partner beside him, he drives off down the highway into the distance.


Jay Cocks of Time called the film "one of the most ebullient and eccentric diversions around."[11] Leonard Maltin gave the film three out of four stars, describing it as "Colorful, tough melodrama-comedy with good characterizations; Lewis is particularly fine, but Bridges steals the picture."[17]
Thunderbolt has an 86% "Fresh" rating on Rotten Tomatoes. The RT consensus is "This likable buddy/road picture deftly mixes action and comedy, and features excellent work from stars Clint Eastwood and Jeff Bridges and first-time director Michael Cimino."[18] Thunderbolt has since become a cult film.[19][20]
As a result of this film and Cimino's TV commercial work, producer Michael Deeley would approach Cimino to direct and co-write the Oscar-winning The Deer Hunter (1978)

Author Michael Bliss wrote that while Thunderbolt may appear to be a conventional violent action film with Eastwood in the lead role, the film is more like "a meditation on, than a representation of, the male camaraderie theme" using rhetorical devices such as symbol, camerawork, and allusive dialogue to add to that theme.[24] According to Bliss, the film's structural paradigm describes a tripartite series of events: natural order followed by disturbance followed by a restoration of natural order