Upon watching “After Love,” the new picture written and directed by Aleem Khan, one can’t help but realize how frivolous, how transitory and callow, most movies must be considered. Knowing that this is Mr. Khan’s debut as a maker of feature films, one’s admiration intensifies toward amazement. 

“After Love” is a rare entertainment, a story geared toward complicated states of mind, awkward questions, and the steep betrayals sometimes fostered by love. Mr. Khan could have settled for the ready gratifications of melodrama or, given the suspenseful nature of several sequences, the cheapjack travails of a psychological thriller. Truth be told, both genres apply, but only as touchstones, not as landing points.

At the center of the film is Mary Hussain (Joanna Scanlan), who we initially see coming home from a family celebration with her husband Ahmed (Nasser Memarzia). The camera is on Mary while she’s in the kitchen; Ahmed, situated toward the back of the frame, is getting comfortable in the living room. Idle, somewhat gossipy chit-chat ensues — the kind of thing couples engage in after years of marriage. 

Mary removes her hijab and immediately sets a kettle on the boil, as befits a good citizen of Dover on a sunny afternoon. She brings Ahmed his afternoon repast. Mr. Khan’s camera doesn’t follow Mary as she ventures into the far room, preferring to keep a polite distance from the events on hand. We quickly intuit that all is not well: Ahmed has died in the few moments it takes to brew a cup of tea.

The local Muslim community turns out in full force to offer Mary what solace they can. In stunning contrast to the surrounding women, Mary is clad, head-to-toe, in stark white. White, in this case, may be an indicator of humility, but it’s also a reminder that this particular widow is a convert to Islam. Mr. Khan can be forgiven some fairly obvious symbolism if only because his compositional knack is so bracingly over-the-top.

Mary’s demeanor is reserved and industrious when dealing with her husband’s death. Her one indulgence is listening to the last message left by Ahmed on her cellphone. He sounds chummy on the recording, giving tidings you’d expect from a husband who spends significant time away because of his duties as a ferryboat captain. Otherwise, Mary begins to sort through Ahmed’s belongings and, by fiat, her own state of mind.

Mary’s stoicism is tested while shuffling through Ahmed’s wallet. Buried among the usual array of mundane items is an ID for a woman who resides in Calais — a regular stopover for Ahmed’s work. A cursory look at his cellphone reveals a series of intimate and, indeed, loving text messages to an unknown number. Mourning gives way to heartbreak, but also, and with no less intensity, curiosity. Mary books a trip to France.

Mary takes a room in Calais and gets up the gumption to visit the home of Ahmed’s paramour. The door is opened by Geneviève (Nathalie Richard) and what transpires is a scene of mistaken identity that could have been lifted from an Abbott and Costello movie if it weren’t fraught with emotional peril and peppered with sly digs about class presumption.

Geneviève mistakes Mary as hired help, as a representative from an agency that’s been sent to help her get ready for a move to new digs. Mary, who is less taken aback than you might guess, agrees to be the new cleaning woman, keeps mum, and immediately starts on her duties. What better way to find out more about this willowy blonde than scrubbing her tub and straightening her bedroom?

At which point, “After Love” takes some startling twists — some of them cruel, some of them tender, and all of them convincing. Mr. Khan grounds the narrative with a deft sense of rhythm, allowing fractious situations and unruly emotions to gain in quietude and consequence. He’s helped, in significant measure, by Ms. Scanlan, an actress known for her comedic gifts seen here flexing impressive dramatic muscle.

“We don’t,” Mr. Khan has stated, “need to understand everything all the time.” He has achieved just that kind of poetic ambiguity with “After Love,” a film that will haunt the viewer long after the lights have gone up.