When you have a magical Egyptian tablet that brings museum exhibits to life every night, the possibilities are fairly endless—cavemen, statues, paintings, and dinosaur bones can all start roaming the halls, causing no end of mayhem. And in the first two Night at the Museum movies, screenwriters Robert Ben Garant and Thomas Lennon (Reno 911!) had a field day— giving us memorable characters like the Einstein bobble-heads, Amy Adams’ Amelia Earhart, and the “dum-dum” Easter Island head.

Now we arrive at the third (and final) installment of the series, and Garant and Lennon’s absence is, alas, unfortunately obvious.

Taking over the screenplay duties for Night at the Museum: Secret of the Tomb are writing partners David Guion and Michael Handelman, whose last effort was 2010’s abysmal Dinner for Schmucks. And while they come up with a few new characters, there’s too much flat, recycled material for Tomb to stack up against its predecessors.

This go-round, we learn that the tablet’s power is quickly fading and that only an immediate visit to the British Museum in London can save it, so night guard Larry (Ben Stiller) rushes across the pond with his son (Skyler Gisondo) and “living” exhibits including Teddy Roosevelt (Robin Williams) and mini Jedediah (Owen Wilson). Once in London, we get Rebel Wilson as a night guard (taking up the mantle Jonah Hill wore in the second film) and Dan Stevens as the resurrected shining knight Lancelot. The supposed race against time, though, ends up feeling more like a lazy meander, and even an all-hands-on-deck battle against a ten-headed dragon isn’t enough to get things going. The only bit of inspired action comes when Larry and Lancelot find themselves trapped in MC Escher’s mind-bending ‘Relativity’ staircase.

Director Shaun Levy seems to have been content just putting everything on auto-pilot, and the movie is rescued only by the cast. Stevens is very fun, as is Rebel Wilson, and the late Robin Williams (in his last on-screen role) does what he can with a woefully underwritten part. And though Stiller is just flat-out stale as Larry, his other role, as a doppelganger caveman, provides many of the film’s funnier moments.

While there’s certainly nothing criminally wrong with Tomb, it is a bit disappointing as a finale. And it only affirms the decision to finally close this museum for good.

3/5 stars