Time to rent a selection of classic American horror movies - because if you don't know your Blades from your Nightmare On Elm Street, Raf Simons's Calvin Klein show is going to make little sense. First up on your buffering bar should be Rosemary's Baby, so you can throw out lines such as "It's going to be a very special party", Mia Farrow-style, in a baby blue dress inspired by her character's night gown.