"The Trap" is the sixth episode of the first season of the American post-apocalyptic drama television series Fallout. The episode was written by co-executive producer Karey Dornetto and directed by Frederick E. O. Toye. It was released on Amazon Prime Video on April 10, 2024, alongside the rest of the season.

The series depicts the aftermath of an apocalyptic nuclear exchange in an alternate history of Earth where advances in nuclear technology after World War II led to the emergence of a retrofuturistic society and a subsequent resource war. The survivors took refuge in fallout shelters known as Vaults, built to preserve humanity in the event of nuclear annihilation. In the episode, Lucy and Maximus discover more about Vault 4, while Howard's past is explored.

The episode received very positive reviews from critics, who praised the flashback sequences and writing.

Howard introduces Vault 4 for a Vault-Tec commercial. After filming, he is introduced to Bud Askins, a Vault-Tec executive. Howard dislikes Askins, as his connections to West-Tek caused many of his friends and allies to die during a battle in Alaska, due to a defect in the T-45 Power Armor. At a party, Howard talks with English actor Sebastian Leslie, lamenting that his commitment to Vault-Tec caused him to be fired from a film. Sebastian, who has sold his voice rights to be used for Mr. Handy robots, suggests that Howard leave Hollywood and "become a product."

At Vault 4, Lucy and Maximus are introduced to Birdie, a Shady Sands survivor, and Benjamin, the one-eyed Overseer. Many of the residents are from Shady Sands, with Vault 4 opening its doors to anyone on the surface. While Lucy suggests having sex with Maximus, his training at the Brotherhood made him lose interest in sex, as well as cause confusion in him about certain details. As Maximus enjoys the benefits of his new home, Lucy decides to explore the area, being told by Ben that some of the inhabitants are victims of mutation. She discovers a classroom, and unfurls a New California Republic flag.

Waking up in the supermarket, the Ghoul is captured by a pair of sheriffs claiming to be working for the Govermint (sic). He is brought before the Govermint's self-titled President, Sorrel Booker, and turns down his suggestion of working with him; Booker then sentences him to death. The Ghoul quickly kills the sheriffs but, before he leaves, is astounded to find a bounty poster of a woman he claims to know, who Booker identifies as Moldaver. In a flashback to the pre-war days, Howard meets with his friend at a covert meeting to discuss a conspiracy theory about Vault-Tec's business model – they cannot sell vaults if people believe peace is imminent. He meets the group's leader, Miss Williams, a younger Moldaver.

Back at Vault 4, Lucy is taken aback when she sees the inhabitants perform a ritual wherein they strip nude, cover themselves in ashes and drink blood, worshipping Moldaver as "the Flame Mother". She descends to the forbidden level 12 and discovers that the inhabitants are regularly experimented on. She watches a video of a woman giving birth to gulpers only to be consumed by them, and also discovers several cryogenic sleep pods of other pregnant women. Birdie and other Vault 4 dwellers capture her as Maximus happily watches television in his room, enjoying luxuries he had not known on the surface.

The score is composed by Ramin Djawadi. The episode featured many songs, including "Theme from A Summer Place" by Percy Faith, "Lonely Hours" by Gene Armstrong and His Texas Nite Hawks, "Summer in Love" by I Marc 4, "Give Me the Simple Life" by June Christy, "Skitter Skatter" by Metrotones, and "I'm Tickled Pink" by Jack Shaindlin.