THE title of writer/director Alex Garland’s film is part of the Latin name for the technique of introducing a character into a stage play with the function of resolving a seemingly insoluble issue.

“Ex Machina” is science fiction, but not the mindless populist kind that besmirches the screen with power struggles, battles in outer space, monsters and destruction. Three characters play out a plot in which the mad scientist (for all time an obligatory element of the genre that Mary Shelley invented when she published “Frankenstein” in 1823) creates a humanoid that proves difficult to control.

Having built the world’s largest internet company, squillionaire Nathan (Oscar Isaac) has retired to an uber-hi-tech house in a remote valley to develop artificial intelligence. Domineering, boorish, alcoholic and manipulative, Nathan has invited his company’s talented coder Caleb (Domhnall Gleeson) to spend a week at the house to help test his latest invention, the direct descendant of Mary Shelley’s. But Nathan’s robot doesn’t just walk around and obey pre-programmed instructions. The latest of a development series has that acme of robotic design – AI. Not artificial insemination but artificial intelligence.

Nathan has installed the Beta test version of AI in the nubile body of Ava (Alicia Vikander), smart, brave, capable of emotion. Caleb’s task is to find its limits. The action and dialogue that Alex Garland has devised between that trio and the house, the lighting in which has subtly spooky capabilities, deliver that essential element that too many modern sci-fi movies fudge – credibility. That makes “Ex Machina” special.

At Dendy