Brick Joke/Theatre

"Man:
 * Derren Brown's stage show Something Wicked This Way Comes relies on this trope: throwaway lines throughout the show that the audience barely notices at the time come together at the end to reveal that he's been leading them towards a certain conclusion. Namely, . At least, that's how he claims the trick works.
 * Also in his latest show Enigma, at the start he makes derogatory references to . At the end of the show, after the lights come up Enigma.
 * A wonderful near-literal example: The during the clowns' "space" adventure in Cirque Du Soleil's La Nouba.
 * There's a minor one in Big River. Near the end,
 * Spamalot has one about the shrubbery. After encountering the Knights of Ni, Arthur says "Where are we going to get a shrubbery?" Patsy says "We can build one. Out of cats." Arthur says "Where are we going to get cats?" Later, during Always Look On the Bright Side of Life, a woman with a shrubbery comes over, and she says "I'm throwing it out. The cat won't leave it alone."
 * The Norman Conquests is a Farce that spans three different plays in the same time frame. When a character exits one room, he appears in another scene in a completely different play. As a result, 70% of the laughs come from repeat audiences who catch the elaborate brick jokes.
 * Shakespeare's The Comedy of Errors: Aegeon and both sets of twins are accounted for from the beginning of the play. But it isn't until the last act that the Abbess appears and turns out to be Aegeon's long lost wife and the Antipholi's mother.
 * In "Tradition," the opening number from Fiddler On the Roof, Tevye says that one of these traditions in his village, Anatevka, is that the men always wear their hats and prayer shawls to show their constant devotion to God. When he rhetorically asks how this tradition got started, he admits that he doesn't know. Then, shortly before the final number of the show, "Anatevka," after, we have this conversation.

Tevye: Maybe that's why we all wear our hats."


 * The old man from A Funny Thing Happened on the Way to the Forum, an initially minor character who is told randomly to walk seven times around the mountains, then forgotten by everyone, hobbles across the set every few scenes announcing how many times he's up to.