Lowly theme park mechanic Sam dreams about his​ childhood sweetheart Sue. With the misguided belief​ that only a bling ring can win the girl of his dreams, Sam​ plans the most perfect night to propose to his one true​ love. But when supervillain Oscar shows up with an evil​ scheme involving a ring of his own, Sam's plans are​ thrown into utter disarray.

After mistaking each other's​ rings for their own, Sam teams up with his robot​ superheroes to track down his engagement ring and​ save the city... learning that it's not about the size of the​ bling, but the size of your heart.​