In adapting Terence Rattigan’s 1952 play The Deep Blue Sea for the screen, director Terence Davies (The House of Mirth) has exorcised a significant portion of the story and eliminated a significant number of characters. Which wouldn’t be a problem, if it weren’t for the fact that, in the process, he’s also jettisoned one more fairly significant element: the point.

What’s left of the play fails to make much of a movie. Rachel Weisz smokes and stares out the window for the better part (and I use that term loosely) of its 98-minute running time. She plays Lady Hester Collyer, an Englishwoman who’s traded marriage to a much older High Court Judge for a doomed affair with a former RAF pilot played by the ubiquitous Tom Hiddleston.

The story unfolds over the course of a single day in a bombed-out corner of London, “sometime around 1950.” As reconfigured by Davies, it’s a chronicle of emotional wreckage. In case we don’t pick up on this, the filmmaker helpfully pans from heaps of rubble in the street up to the boarding-house window where Hester stands gazing, inhaling and thinking emotionally wrecked thoughts. She starts her day by attempting to commit suicide.

Our heroine lives to puff another day, however, thanks to the intercession of her landlady (Ann Mitchell) and a mysterious tenant (Karl Johnson), who offers medical treatment but insists he’s not a doctor. This character, it should be noted, is among the most significant in Rattigan’s play. The work’s resolution would not be possible without him. Davies does neither the film nor the viewer any favors by reducing him to a walk-on.

Hester’s problem? Well, it’s difficult to say exactly, but it apparently has something to do with passion. She abandoned her devoted but humdrum husband in the hope of experiencing a fuller, more fiery love, but, after a brief honeymoon phase, the spark has gone out of the affair. Hiddleston’s Freddie Page has turned out to be something of a disappointment. He’s consumed by thoughts of the war and consumes way too many pints as a result.

Fate denies the pair a chance to rekindle their romance by means of a ham-handed maneuver. Hester forgets to remove her suicide note from the mantel where she left it for Freddie to find — and, sure enough, he finds it. His reaction upon reading it is so over the top and out of nowhere that one can’t help suspecting Davies of cutting crucial scenes leading up to this point. The last thing one expects the ex-soldier to do is have a hissy fit and leave his lover. Nonetheless, because he feels Hester’s suicide attempt reflects poorly on him, that’s pretty much the last thing in the film Freddie does.

Which, of course, only encourages the emotionally damaged Hester. At this point, she has more to stare out the window and have flashbacks about than ever — something that, believe it or not, doesn’t become more compelling to watch over time. Not that The Deep Blue Sea is ever particularly compelling to watch.

Besides the minor detail that, in Davies’ stilted, stripped-down adaptation of the play, little of interest actually happens, there are other problems. For one, Weisz is woefully underutilized. She’s far too talented an actress for material this melodramatic and shallow. The editing is sloppy. It’s impossible in spots to tell whether events take place in Hester’s present or past. The violin score is intrusive and overwrought. Finally, Hiddleston’s role is so poorly conceived that it’s likely to prove a footnote to his more fully realized work as Thor’s evil brother Loki in the Marvel movies.

To be fair, Davies’ latest does offer an effective evocation of postwar Britain and succeeds in paying homage to such films of the ’40s as Brief Encounter. All the same, one wishes it had been briefer.