In a neighbourhood of Paris where a series of murders have taken place, aspiring Lithuanian actress Daïga strives to achieve her dream. Meanwhile, immigrant musician Théo struggles to raise his son with the intention of returning to his native Martinique. Théo’s brother, Camille, is a gay performer who makes ends meet by dancing at a cabaret.

I Can’t Sleep is a period piece set in the 1980s when real-life serial killer Thierry Paulin, who — together with his lover — murdered more than twenty elderly women in Paris’s 18th arrondissement.