Producers: Jack Selby, Lily Collins, Jesse Plemons, Charlie McDowell, Jason Segel, Duncan Montgomery and Alex Orlovsky   Director: Charlie McDowell   Screenplay: Justin Lader and Andrew Kevin Walker   Cast: Jason Segel, Lily Collins, Jesse Plemons and Omar Leyva   Distributor: Netflix

Grade: B- 

So long as you don’t expect anything especially clever, “Windfall” is an engagingly nasty little home-invasion thriller, a chamber piece whose excellent cast goes far to make up for its logical lapses and redeem its sour attitude.

The sole location is a gated estate somewhere in southern California, with a handsome modernistic house, grandiose gardens, a pool with sauna and little cabins, and groves of trees.  As the film opens, a lanky, scruffy interloper simply called Nobody (Jason Segel) has ensconced himself there, sampling its creature comforts and rifling through shelves for money and valuables.

His sojourn is interrupted by the unexpected arrival of the owner, simply called the CEO (Jesse Plemons), and his attractive young wife (Lily Collins), who, we learn, directs his foundation.  Nobody tries to slip out, but gets noticed, and so takes the couple prisoner.  He decides to lock them up and leave with what he’s already collected, but on spying a security camera returns and demands a larger sum of cash.  He and the CEO agree on the amount, but it will take some time for it to be delivered.

Inevitably, things happen during their time together.  A garrulous gardener (Omar Leyva) shows up, with unfortunate results.  The relationship between the CEO and his wife shows signs of strain, deriving from his condescending, controlling attitude and her dreams of what might have been.  Attempts to escape are foiled, and the CEO’s periodic needling of Nobody causes the friction to amp up.

In the course of all this, socio-political issues inevitably arise.  The CEO is convinced that Nobody must be a disgruntled ex-worker who was terminated at one of the companies where his tech innovations led to staff reductions, and repeatedly pesters him for details, in the process lapsing into crass generalizations about freeloaders and layabouts that irritate not only his captor but his wife, who harbors more charitable views.  As such matters swell up, the CEO, with his smarmily superior attitude, becomes the fulcrum around which the plot circles as the other characters respond to him.  Understandably Plemons is thus the dominant figure in the cast, and the actor, usually cast in more sympathetic roles, displays a supercilious, unlikable side very convincingly.  That’s not to say that Segel and Collins don’t do capable work, but in a more reactive mode.

It’s in this interplay that the script occasionally lurches into comically implausible territory.  It’s an amusing, but extremely unlikely, bit of business when the CEO and his wife argue with Nobody about the amount of money he should demand for their safety, insisting that $100,000 is far too little to meet his needs and finally bidding him up to $500,000.  A chase sequence through the estate groves lacks the choreographic dexterity that would have made it truly funny; instead it comes off as just messy.  The same might be said of the gardener’s final scene, which tries to mix farce with a morbid tone to only middling effect.

The occasional turn to seriousness fares even worse, most notably when Nobody and the wife have a heart-to-heart in the courtyard at night as the CEO sleeps.  It paves the way to the final twist, but really doesn’t adequately prepare one for it, as downbeat as it is.

Nonetheless, thanks to the skilled performances the film works its way through the narrative bumps and remains engrossing, if not entirely convincing, to the bitter end.  The script by Jason Lader and Andrew Kevin Walker (whose writing career after the unforgettable “Se7en” has disappointed) contains an occasional choice moment, and McDowell, cinematographer Isiah Donté Lee and editor David Marks manage to keep things coherent and visually interesting—the latter due in no small measure to Andrew Clark’s production design.  The mood of suspense is aided by the sound design of Frank Gaeta and, especially, the score by Danny Bensi and Saunder Jurriaans, which sounds, particularly at the start, like a slimmed-down version of Hermann’s “Vertigo” music, and retains nods to that composer’s distinctive style throughout.

“Windfall” might not bring the enormous treasure the title suggests, but if you keep your expectations low it will provide a nice little return on the time you invest in it.