Oscar Isaac, left, and Domhnall Gleason in “Ex Machina.” (A24 Films)

In Alex Garland’s moody, thought-provoking sci-fi thriller Ex Machina (rated R), people use people and people use machines, so it’s only natural that machines might also use people. That’s cynical stuff, and to be sure a strong thread of cynicism runs through Garland’s story. But there’s also that sense of hope that comes with discovery: The characters are opening doors that have never been opened before, and they’re not quite prepared for what might be on the other side.

Garland is an ace screenwriter who cut his teeth working with Danny Boyle on 28 Days Later (2002) and Sunshine (2007), so it’s not surprising that he would efficiently set the stage for his directorial debut. In the first five minutes or so we learn that Caleb (Domhnall Gleason), a computer programmer for the world’s largest search engine company, has won a lottery to spend a week at the secluded estate of his reclusive employer Nathan (Oscar Isaac).

Much of the estate appears to be an underground, concrete-walled bunker, and Nathan tells Caleb that’s because it’s actually a research facility. Nathan has what we would call a terrible work-life balance, and he’s brought Caleb into his inner circle not for a vacation, but for a project. For the next week Caleb is to interact with Ava (Alicia Vikander), a humanoid artificial intelligence Nathan has built from scratch. The inventor needs a third party to test-drive Ava’s A.I. and see if she really represents the quantum leap that programmers have lusted after for generations.

Nathan, we soon learn, is a true genius and a genuine jerk, but Caleb quickly moves from being in awe of his boss to being enamored of his boss’s creation. In a series of interview sessions with Ava, the wide-eyed programmer finds himself falling for this exotic mélange of ladylike curves and exposed wires. Vikander, a Swedish actress with only a few past roles under her belt, uses her onscreen anonymity to her advantage: She comes across as a true cipher here, and we’re so busy being impressed by Ava’s self-awareness that we forget what it might mean if this machine is really self-aware.

For his first time behind the camera, Garland shows no trace of uncertainty: He draws definitive performances from his actors without having them say aloud every thought that obviously crosses their minds. (This effect is particularly powerful with Nathan, played by Isaac with just the right balance of enigmatic arrogance and vulgar friendliness.) The austere interiors of Nathan’s concrete palace are beautiful yet claustrophobic, creating an atmospheric soup of the perfect temperature for these characters and their surreal journey.

It feels important somehow not to give away too much of what actually happens in Ex Machina; there’s a thrill of seeing it for yourself that shouldn’t be denied. This is an important film – the best movie of the year, so far, and a once-a-decade sci-fi experience that addresses big issues in an utterly relatable way. Remember that sense of discovery I mentioned above, the ones that the characters encounter? Audiences are about to discover something too. Go see Ex Machina. You’ll want to be there when Nathan, Caleb and Ava start opening those doors.