A goofy little joke or prank, a crime, or a ridiculous adventure is called a caper. For example, your quest for an American newspaper turned into a caper that took you all over the Irish countryside.
Caper originates from the Italian word capriolare, meaning “jump in the air,” and indeed, one meaning is "frolicking play or light-hearted dancing." Little kids like to caper at family parties — it gets them tons of attention. Other kinds of capers might get you jail time because a caper can also be an outlandish crime spree, or a wild activity. Finally, capers are the very flavorful pickled flower bud found in Mediterranean cooking.