Producers: Maxime Cottray, Nate Bolotin, Sean Sorensen, Matthew B. Schmidt, Leonora Darby and James Harris   Director: Guillem Morales   Screenplay: Morgan Lloyd Malcolm   Cast: Naomie Harris, Natalie Dormer, Dominic Allburn, Jack Morris, Leah Mondesir-Simmonds, Olivia Juno Cleverley, Isobel Hawkridge and Rupert Holliday-Evans   Distributor: Shout! Studios

Grade: C+

Guillem Morales’ psychological thriller is basically a story of revenge; the question is against whom?

At the start the answer seems simple.  Heather (Naomie Harris), a well-to-do housewife obsessed with the wasps that appear to have infested her suburban home, looks up her erstwhile schoolmate Carla (Natalie Dormer), a pregnant checker at a supermarket with a layabout husband (Jack Morris), an ill father (Rupert Holliday-Evans) and a brood of children already.  Carla’s understandably unhappy with her lot and angry about things.

She’s also inherently prone to violence.  An early flashback to the women’s schooldays shows her (Olivia Juno Cleverley) crushing a wounded bird with a rock as young Heather (Leah Mondesir-Simmonds) looks on horrified.  Later flashbacks will add to the picture of their relationship as girls.

Now Heather has a proposition for Carla, whom she hasn’t seen in years: she’ll pay handsomely if her old classmate will kill Simon (Dominic Allburn), her domineering, unfaithful husband.  In a session at Heather’s home, the women discuss almost giddily the possibility of Heather avenging her mistreatment at Simon’s hands through Carla.

In the process other matters are raised, including Heather’s desire for a child and Simon’s fascination with insects, particularly the tarantula hawk, a spider wasp that preys on tarantulas, paralyzing the spider and laying an egg inside its body; the wasp larva feeds on the spider from within until it emerges and the host dies. 

All of these elements and more combine in the twists that follow in the movie’s second half; how they do so won’t be revealed here, since that would spoil the surprises the film has up its sleeve.  Suffice it to say that the revenge plot becomes increasingly complicated as more revelations, past and present, accumulate.  One of them, it must be said, is a complete coincidence that in retrospect strains credulity.  And the final turn involves one character’s ability to predict what another’s action will be in a particular circumstance and then be willing to suffer the consequences when the prediction proves correct.

In other words, in order to be satisfied with “The Wasp” a viewers need to be able to suspend disbelief in much the same way as with a play (and film) like “Sleuth.” Though it’s a far darker piece than Anthony Shaffer’s light entertainment, like it this is basically a two-hander in which Heather and Carla jockey for dominance as the plot gains momentum.  Whether you’ll find that it works in the end will depend on your tolerance of narrative contrivance, and of the rather ugly metaphor the titular creature represents.  But whatever the reservations about plausibility, it’s undeniable that Morales effectively ratchets up the tension as the story proceeds.

It’s undebatable, too, that both Harris and Dormer give bravura performances as the women who share an uncomfortable past and an increasingly stressful present.  Harris has the greater emotional canvas to traverse—in contrast to the more vulnerable Heather, Dormer’s Carla is rather one note—but each is excellent (as are Mondesir-Simmonds and Cleverley as their younger versions).  Everyone else, including Allburn as the adulterous Simon, is okay, but golden-haired Isobel Hawkridge is a charmer as a little neighbor with a pivotal role to play in how things turn out.

This is a modest film technically, but the production design of Elizabeth El-Kadhi is impressive, the interior of Heather’s home being especially well done (the photographs of various insects on the stairwell wall are striking), and it’s nicely caught by cinematographer John Sorapure.  Editors Ryan Morrison and Joe Randall-Cutler bring in the film at a trim hour-and-a-half, and Adam Janota Bzowski’s score is effective without being overpowering.

“The Wasp” has some glaring plot holes, but if you’re willing to overlook them it carries a sting.