The bad guys in Breaking In (henceforth known as Reverse Panic Room) make the Wet Bandits from Home Alone look like Ocean’s 11. They get a vague tip about a safe stuffed with millions in cash that's hidden in a house in the woods of Wisconsin. Then they kill the guy who owns the safe and break into the house, apparently never once considering the man’s family may swing by to put his affairs in order. They do, and then the crooks basically spend 90 minutes getting outsmarted and beaten at every turn.

This is surely intended as part of Reverse Panic Room’s appeal. Moms deserve their power fantasies just as much as anyone else, and this one envisions a scenario where a mother of two with no apparent military or police training can fend off four armed psychopaths with ease. Gabrielle Union plays the mom, and it is pretty fun watching her go Rambo by way of MacGyver on these numbskulls — at least for a while.

Almost the entire film is set inside the house with the safe — except it’s no ordinary house. It’s basically a handsomely furnished fortress with automated locks, extensive security cameras, and motion detectors. From either a bank of computers in the basement or a touchscreen remote you can monitor every inch of the house for intruders. No one could possibly penetrate a house this secure! Naturally, the four boobs looking for the safe manage to get in completely undetected while Union’s Shaun is out in the driveway sipping a glass of wine.

That unlikely series of events creates a tense standoff: The crooks have Shawn’s kids, Jasmine (Ajiona Alexus) and Glover (Seth Carr), and they’re barricaded inside. The phone line’s been cut, which means the thieves have just 90 minutes to break into the safe and make their getaway before the security company shows up to check on things. Shaun is outside with no phone and, in an obvious nod to Die Hard, no shoes. How will Shaun break in and save her family?

Very easily as it turns out! The most disappointing part of Reverse Panic Room is how little it exploits its high-concept premise after spending so much time establishing all the particulars of this fortified lake house. Before you know it, Shaun is back inside with almost no fanfare or explanation. This Reverse Panic Room has a bunch of reverse Chekhov’s guns too; chess pieces it puts on the board and never moves. There’s a reverse Chekhov’s security system, a reverse Chekhov’s drone, a reverse Chekhov’s stairwell covered in gasoline. There’s all this setup and so little payoff.

Granted, the sight of Gabrielle Union beating the crap out of these nerds is fun. Union makes a solid action hero; determined but not invulnerable. And Billy Burke, as the leader of the goons, projects the right vibe of no-nonsense menace. These players could be the stars of the mother of all home invasions.

Instead, they’re let down by Ryan Engle’s unimaginative script and the pedestrian direction by James McTeigue. (This may be Reverse Panic Room, but McTeigue is no David Fincher.) He chose to shoot the movie in widescreen, and the 2.35:1 aspect ratio does the claustrophobic atmosphere no favors. No matter how bad it gets, Shaun never really feels trapped or helpless.

Again, maybe that’s what they were going for. Reverse Panic Room seems less focused on building suspense than in watching Gabrielle Union kick an improbable amount of butt. Burke’s Eddie keeps derisively telling Shaun she’s an “impressive woman”; that her survival skills aren’t bad for a lady. Then, of course, she turns the tables on him. There’s a certain amount of pleasure in that. There could have been more, though, if she had some worthy adversaries, and a worthier script.