A family vacationing in their secluded summer home is terrorized by doppelgangers in the new horror-thriller “Us,” a movie that promises an engaging mystery as it begins but ends with a head-scratching reveal. It’s also writer-director Jordan Peele’s follow-up to “Get Out” and proves that not only is the sophomore slump a very real thing but sometimes going bigger isn’t always better.

“Us” begins well enough, introducing us to the Wilson clan as they bond en route to their vacation spot in Santa Cruz. Patriarch Gabe (Winston Duke from “Black Panther”) is playful, while mother Adelaide (Oscar winner Lupita Nyong’o) holds down the emotional fort. She also has unfinished business in Santa Cruz stemming from a childhood incident where a hall of mirrors literally took her breath away. This is the first sign of logical trouble for “Us” since we’re told Adelaide’s trauma in Santa Cruz was so severe she came within inches of going insane. The family’s beach destination is the exact same spot from the earlier ordeal and yet despite that fact Adelaide can only muster mild hesitation before deciding to put her husband and two young kids in harm’s way. In a better screenplay this would serve as a clever way of foreshadowing a bigger reveal down the line but here it’s only meant to cut corners and lazily advance the story.

The foreboding dread eventually arrives late at night while the Wilsons are getting ready for bed. Four menacing figures —two adults and two kids, all dressed in red jumpsuits and holding golden shears— are shown standing in their driveway. What they want isn’t initially made clear, but the more we see of them the more it feels like “Us” is getting ready to give us another “Funny Games” remake. But those thoughts are soon dashed as we learn the figures in the driveway are exact replicas of the Wilsons and what these doppelgangers want is just as dumb as their fashion sense.

“Us” is a movie best served short, a spark of an idea stretched to feature length with nowhere to go. Writer-director Jordan Peele gets credit for originality but swinging for the fences doesn’t mean you get an automatic pass. You still have to steer the plane and land it safely, not just have a smooth takeoff and crash on arrival. That loud crash is exactly what “Us” does in its final moments when all is revealed. What is meant to be a clever pat on the back instead leaves us questioning everything that came before. That’s not a good sign for a movie trying to pull off a magic trick on its audience. You want them leaving the theater amazed, not seeing through your transparent sham and laughing at all the dumb character motivations until the last layer of its cinematic onion is peeled (no pun intended).

Rating: C+

“Us” is now playing in theaters nationwide.