“You’re ___ something”

ONTO

Not available

This clue plays on a common phrase where "onto" means discovering or realizing something important. When someone says "You're onto something," they’re suggesting you’ve uncovered a useful idea or truth. The blank hints at the preposition "onto," which fits both grammatically and idiomatically in the sentence. It’s a straightforward fill-in-the-blank with no hidden wordplay—just a natural-sounding expression.