A good Doctor becomes a Bad Samaritan in this dopey but fun thriller

Ethics studies tend to start subjects off with some easy dilemmas before moving on to the really tough decisions. They might initially ask, for example, whether you’d leap into the ocean to save someone who’s drowning, even if doing so would ruin an expensive pair of shoes (that there’s no time to remove, let’s say). Any non-sociopath would answer “yes” to that one—it’s a simple matter of weighing minor material loss against an irreversibly horrific outcome. Not worth wrestling with. Let’s get to the trolley problem.

At first, the plot of Bad Samaritan, an enjoyably dumb thriller written by Brandon Boyce (Apt Pupil, Wicker Park) appears to be predicated on the unconscionable response to a straightforward situation. Sean Falco (Robert Sheehan), an Irish expat living in Portland, Oregon, has devised a small-time larceny operation with best friend Derek (Carlito Olivero): Having persuaded a restaurant to let them do valet parking, they use the cars’ navigation systems to drive to nearby homes, gain entry via the garage-door opener and/or the keys, and steal a variety of small items that aren’t likely to be noticed missing right away. One night, while robbing the (improbably unalarmed) home of a dead-eyed billionaire named Cale (David Tennant, the 10th Doctor Who), Sean discovers a terrified woman (Kerry Condon) chained to the floor of his office, along with lots of evidence that Cale is a serial killer specializing in bodily dismemberment. If Sean calls the police, however, he might be arrested himself, and perhaps even deported back to Ireland.

This is not remotely a difficult decision (even ignoring the strong likelihood that helping to apprehend a serial killer earns you a pass on second-degree burglary), and Bad Samaritan, despite its title and to its credit, does not pretend for very long that it is. Instead, the film becomes a highly implausible but reasonably gripping cat-and-mouse duel between Sean, whose efforts to alert the cops and the FBI repeatedly go nowhere, and Cale, who quickly realizes which peon has discovered his secret and takes sadistic revenge. Cale boasts some inexplicable superpowers, like somehow being able to completely redesign entire rooms of his house in nothing flat, but Tennant makes him amusingly deranged, with a supercilious air that suggests a sense of entitlement, based on inherited wealth, that’s crossed the line into homicide. The character gets an unnecessary childhood backstory, but at least he’s a memorably repugnant villain.

Our hero, by contrast, comes across as somewhat bland, though Sheehan is likeable enough. It doesn’t help that the movie places far too much emphasis on Sean’s personal jeopardy, at the expense of the woman Cale is still holding prisoner. After seeing the billionaire’s murder room, with its vast array of torture implements, it’s hard to get too concerned about Cale downloading a mild semi-nude photo of Sean’s girlfriend (Jacqueline Byers) and texting it to all of Sean’s Facebook friends, causing her to dump him. Hey, remember the woman who might get diced up at any moment? Bad Samaritan was directed by Dean Devlin (best known for writing a bunch of Roland Emmerich blockbusters in the ’90s: Stargate, Independence Day, Godzilla), who’s still struggling with basic visual coherence; his failure to think in terms of compositions and cuts forces editor Brian Gonosey to bridge certain scenes with clunky dissolves, hobbling an otherwise speedy pace. Still, this comparatively low-budget effort represents a marked improvement from Devlin’s debut theatrical feature, Geostorm, which was among last year’s very worst films. He’s graduated from painful tedium to an acceptable means of killing two hours. One step at a time.