Truly alien creatures are hard to relate to because they’re so, well, alien. The best-realized ones have different cultures and biologies and belief systems that make them distinct from humanity and, thus, hard to understand. The alien in the Netflix film Spaceman is one recent example: a giant spider with squirming tentacles, a disturbingly human mouth, the calming voice of Paul Dano, and the ability to experience time nonlinearly. And yet, the weird critter is also very relatable. He’s nosy and perceptive and prone to creature comforts to ease stress; he’s creepy, sure, but I kind of love him. And paired with a remarkably restrained Adam Sandler as a burned-out astronaut, his presence makes for some sad and soothing science fiction.

Directed by Johan Renck and based on the novel Spaceman of Bohemia by Jaroslav Kalfař, Spaceman follows a Czech astronaut named Jakub (Sandler) on a solo journey to explore a strange phenomenon called the Chopra Cloud somewhere near Jupiter. Jakub has few people to talk to — his supervisor Peter (Kunal Nayyar) is always in his ear to keep things on track, and he’s able to video chat with his wife Lenka (Carey Mulligan) thanks to a device that looks like an ’80s arcade cabinet — but he’s physically isolated. Things only get worse as calls with Lenka become increasingly infrequent. This leads to a lot of time spent alone in the quiet of space, thinking.

And then, suddenly, he’s not alone anymore. Very early on in Spaceman, Jakub is joined by a mysterious alien he eventually names Hanus (Dano). The giant spider has a fascination with humans and spent an undetermined amount of time learning our history, language, and customs. But he’s especially attracted to Jakub: as a solo explorer himself, Hanus feels drawn to the lonely spaceman. And once Jakub gets over the shock of, you know, a huge talking spider making a sudden appearance in his otherwise empty world, the two quickly connect.

Hanus has the ability to peer into Jakub’s thoughts and memories, and he uses this to explore his past but mostly to understand his deteriorating relationship with Lenka. It’s a little bit Eternal Sunshine of the Spotless Mind, except Hanus takes on something of a therapist role: from his detached perspective, he’s able to use details from Jakub’s life to figure out how and why things went the way they did and then be brutally honest about his findings. Spaceman starts out as a cute but weird buddy story but eventually morphs into a raw exploration of loneliness and coming to terms with our own personal failings.

Since so much of the film takes place with two characters in the confines of a small spaceship, the performances are a large reason why the movie works so well. Sandler sounds a bit odd at first — he’s sort of doing a Czech accent but also kind of not — but he shows a new side of himself here, one that isn’t outright goofball or tense bundle of nerves. He’s quiet and reserved, with the haggard look of someone struggling both mentally and physically. Dano, meanwhile, is alternately cool and warm, with an alien viewpoint (his race doesn’t experience guilt, for instance) that, at times, becomes sentimental. (It turns out that Nutella tastes a lot like a certain larvae delicacy from his home world.) The two play off each other well: Jakub wants to ignore the truth, while Hanus can’t stop bringing it to the surface.

Eventually, the story comes back to its core sci-fi mystery, and Spaceman does a very good job of tying these threads together in a way that feels natural and ends on a hopeful note, without devolving into a cliche happy ending. It’s sad, yes, but in a cathartic way — and almost makes you want to hug a talking spider. Even if Hanus would never be down for that.

Spaceman is streaming now on Netflix.