The Killing of a Sacred Deer is a 2017 Irish-British psychological horror tragedy film directed by Yorgos Lanthimos, from a screenplay by Lanthimos and Efthymis Filippou. It stars Colin Farrell, Nicole Kidman, Barry Keoghan, Raffey Cassidy, Sunny Suljic, Alicia Silverstone, and Bill Camp. The story is based on the ancient Greek tragedy Iphigenia at Aulis by Euripides. In the myth, Agamemnon, leader of the Greek army against Troy, accidentally kills a deer in one of Artemis’ sacred fields. He is told by a seer that he must kill his eldest daughter, Iphigenia, in exchange. Agamemnon is initially reluctant but is pressured into sacrificing her by his commanders. In some tellings, she is killed, in others she is transported elsewhere, replaced at the last moment with a deer/goat by Artemis. Some versions have her deified by Artemis after being transported.