Quickly assembles, with "up"

RIGS

Think of what a stage crew might do in a hurry to prepare equipment before a show. The word also describes hastily putting together a plan or setup.

The word "assembles" hints at putting something together, which "rigs" can mean—like setting up equipment or gear. The "with 'up'" part is a sneaky indicator that you might initially think of "rigs up," but the answer is just "rigs" because "up" is already included in the clue as a directional hint (common in crosswords). It’s a play on the phrase "rigs up," where "up" is separated out to mislead slightly.