While diving in a remote French lake, a couple of YouTubers who specialise in underwater exploration videos discover a house submerged in the deep waters. What was initially a unique finding soon turns into a nightmare when they discover that the house was the scene of atrocious crimes. Trapped, with their oxygen reserves falling dangerously, they realise the worst is yet to come: they are not alone in the house.

In a near-future Britain, young Alexander DeLarge and his pals get their kicks beating and raping anyone they please. When not destroying the lives of others, Alex swoons to the music of Beethoven. The state, eager to crack down on juvenile crime, gives an incarcerated Alex the option to undergo an invasive procedure that'll rob him of all personal agency. In a time when conscience is a commodity, can Alex change his tune?