With Stowaway, director Joe Penna isn’t really interested in frivolously dwelling on humanity’s place in the stars. It also shirks loud explosions or pioneering visuals, favouring a low-stakes and low-key approach to interstellar travel. Front and centre in this space adventure is a moral dilemma that plays out slowly but compellingly during a manned scientific endeavour to Mars, staying blissfully clear of melodrama for – almost – its entirety and featuring four standout performances. 

Courtesy of Netflix

The crew of a Mars-bound spaceship – commander Marina (Toni Collette), medical researcher Zoe (Anna Kendrick) and biologist David (Daniel Dae Kim) – successfully launch from earth and head off on their two-year round trip to and from Mars. Shortly after take off however, they discover an accidental stowaway on board, launch plan engineer Michael (Shamier Anderson). The immediate consequences of his arrival, and the long-term implications of another human on a ship with strictly limited capacity, put the mission and the crew in unavoidable jeopardy. 

It is easy to be cruel and call Penna’s film slow, but it is more accurate to say that it is patient. This is space travel without hyperspeed, so you are in it for the long haul. Once the situation the crew faces is made clear, the intensity and urgency of the threat they faced is unveiled with admirable restraint. The ship’s artificial gravity is not just a neat touch, but a cleverly used and ever-present metaphor that highlights the weight of the impending decision facing the crew. Not even the endless void of space provides any escape. Until the final half an hour or so, the action is confined exclusively to the inside of the ship, evoking Alien with its claustrophobic low shots of grey, empty corridors and eerie silence. 

Courtesy of Netflix

Add to this a radio communication with Earth where you never hear the other end of the call, and the loneliness imposed on the characters is enough to make even the viewer feel nervous. It is this striking atmosphere and disconcerting environment that draws you in and lets you take in every painstaking minute, as if you were as much a member of the crew as they are. This makes it unavoidably disappointing when the climax seems to throw caution to the wind and let loose with an overly-soppy (if beautifully filmed) ending that feels at odds with the rest of the story.

The cast all excel and make the lives of everyone on board feel like they really matter. Kendrick in particular, better known for performances full of loving vibrancy and emotion, is the standout in a role than on paper is far too stony-faced and realist for her to pull off. Anderson too plays a huge part in preventing the film from sliding towards a heavy-handed lesson in ethics. His reaction to the news about the current situation is a sensational mixture of obvious fear and serenity.

Technological jargon and space chain-of-command speech go out of the window in Stowaway as the human cost of adventure becomes ever more central to the story. Penna doesn’t need to trigger any explosions or load the film with plot to keep you interested. The ending is regrettably weak, but shave off the final 15 minutes or so and you have an impressively finished science fiction drama featuring noteworthy performances from Kendrick and Anderson.

Stowaway is available to watch on Netflix now.