Operation: P.R.O.M.

The Venture Bros. has run six seasons. The first three seasons consist of 13 thirty-minute episodes (including time for commercials), plus the pilot and one 15-minute Christmas special. The fourth season consists of 15 thirty-minute episodes and one hour-long season finale episode, while the fifth season has an hour-long premiere and 7 thirty-minute episodes.

An hour-long special titled "All This and Gargantua-2" aired January 19, 2015, as a precursor to season 6, although the Adult Swim website's video on demand section considers the episode to be the first episode of season 6. In January 2016 the sixth season, consisting of eight episodes, began airing and being made available on various digital platforms on consecutive Sunday evenings.

During the first three seasons, Adult Swim originally broadcast several episodes out of narrative order. The DVD releases present the episodes in the order intended by Jackson Publick and Doc Hammer. Beginning with season four, the network has debuted new episodes in the correct order.

Dr. Venture, Brock, Hatred, Pete, Billy, Orpheus, Jefferson, and the Alchemist decide to throw Dean and Hank a prom to celebrate their "graduation". During the events, 21 enters the Venture Compound to bury 24's skull, as he believes the man's ghost needs to be put to rest, but he is subdued by SPHINX's men. 21 discovers Monstroso's body, whose disappearance has disrupted the Guild of Calamitous Intent, and Shore Leave reveals that they have created a series of fake Monstroso bodies to try to negotiate a deal with O.S.I. to remove them from the list of enemy combatants. However, Monstroso's men are attacking the compound, so 21 is conscripted into joining SPHINX on the assault. Brock has taken Hank and Dean to pick up their dates, with Dean picking up Triana. However, Triana has started dating Raven, a pale young man who requires crutches to walk, and Dean becomes Jealous. Hank fails to take the family's mailwoman as his date, as well as the Quymn twins, but they find Dermott and he tags along instead. Hunter Gathers and Mile High go to O.S.I.'s flying headquarters to negotiate, having to successfully wrestle General Treister to do so. After winning, Gathers informs Treister that he believes there are Guild moles in O.S.I., before Treister begins to convulse and Mr. Doe and Mr. Cardholder come in to subdue him. Gathers is knocked out, and when he awakes he finds the office destroyed, and Treister encased in an expanding foam and reveals that he believes he has become a "Hulk" after experimental gamma ray chemotherapy to treat his metastatising testicular cancer. At the prom, Dr. Venture has hired a cadre of prostitutes to serve as other members of the group, and after propositioning one of them with his name, discovers that his name is apparently synonymous with some abhorrent sexual act. As everyone tries to figure out what exactly a "Rusty Venture" encompasses, the Alchemist begins to realize he may know Shore Leave, and Dean becomes increasingly jealous of Raven before angering Triana so much she leaves. Brock plans to bed one of the prostitutes in SPHINX's headquarters, but he's tranquilized by Molotov Cocktease, disguised as a SPHINX agent.

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Wikipedia