No one is more surprised than me to discover parallels between Shadow in the Cloud and genre festival favorite The Vast of Night. The latter film was celebrated by critics and audiences for its audacious long takes, but also for its emphasis on dialogue-driven performances. The Vast of Night dismissed the conventional adage to “show, don’t tell” by quite literally leaving the camera fixed on actors’ faces for long stretches of time.

Shadow in the Cloud isn’t quite as bold, but the WW2-set film does make the unexpected decision to treat the first half of its roughly 80 minute runtime almost like a radio play. The film, set in the foggy wartime skies above New Zealand, follows female pilot Maude Garrett (Chloë Grace Moretz) as she hops a last-minute ride on a B-17 Flying Fortress with a mysterious package she’s fiercely protective of.

Unfortunately for Garrett, The Fool’s Errand has an entirely male crew, who run the gamut from flat-out misogynist to even-tempered, but unhelpful. After leveraging her way onboard, Garrett is ordered into the small, enclosed turret below-deck, which is where she stays for the better part of the film’s runtime.

What’s astounding about this creative choice is how well it works. Aside from the disembodied audio from the male crew in her headset, Shadow in the Cloud is essentially a one woman show, relying entirely on Grace Moretz to carry the drama. Credit composer Mahuia Bridgman-Cooper for generating atmosphere with a moody electro-synth score and director Roseanne Liang for finding compelling ways to open up the tight confines, including unnerving shots through Garrett’s legs of the glass floor separating her from 9,000 feet of open air below.

Despite being a locked room drama for half of its runtime, the film is never short on conflict. Early on, Garrett struggles with the thinly veiled sexism from everyone on the crew aside from sympathetic Quaid (Taylor John Smith) and young gunner Beckell (Nick Robinson), in addition to being separated from the mysterious bag she’s so desperate to protect. Then as the mission progresses, the B-17 is threatened by both enemy Japanese planes and a pesky man-sized bat-like Gremlin (evoking the classic Twilight Zone story “Nightmare at 20,000 Feet”). Both adversaries are cleverly introduced in the cute animated sequence that opens the film.

As Shadow in the Cloud progresses, though, it becomes harder and harder to ignore the influence of screenwriter Max Landis, the film’s original screenwriter who was dismissed following allegations of sexual assault. Despite a thorough scrub from the production notes (Liang is the sole credited screenwriter), Landis’ shadow looms large over the rote action movie conventions that dominate the film’s back half.

After a sensational first half, the contents of Garrett’s radio bag are revealed and Shadow in the Cloud immediately becomes both a more conventional film and a more bombastic one. The threat from the enemy planes and the Gremlin escalate exponentially, but unfortunately it is in increasingly ridiculous and frustrating ways. This is symptomatic of Landis’ tendency to lean into action movie clichés; one sequence finds Garrett climbing out onto the underbelly of a plane with relative ease is a particularly glaring example of how silly the film has become. Audiences who can suspend their disbelief will find the back half of the film loud and fun, but compared to the quietly compelling first half, it’s tonally jarring.

Grace Moretz anchors the whole enterprise with a surprisingly commanding performance that is reminiscent of her early work in Kick-Ass and Let Me In. The moments when Garrett bristles and rebuffs the sexist comments from the men is easily one of the film’s greatest strengths (Liang’s choice to include real-life photos of women in the RAF over the credits is also particularly inspired). As an action heroine, Grace Moretz is completely believable, even when the events occurring aboard the plane are emphatically not (one moment would be especially egregious if it wasn’t immediately followed by a great comedic stinger and a fantastic reaction by the actress).

Ultimately Shadow in the Cloud is a mixed bag. Despite Grace Moretz’s capable lead performance, Mahuia Bridgman-Cooper’s score and excellent direction by Roseanne Liang, the tense and mysterious first half is completely undermined by a clichéd, ridiculous second half that ends the film on a far more conventional and less satisfying note.