In an opulent and ornate European chateau, set against a backdrop of lavish gardens and stately hallways, an enigmatic man, who claims to be a guest at the hotel, engages a woman in a complex dialogue. He insists that they met the year before at Marienbad and had planned to run away together, although the woman appears to have no recollection of this meeting. The man is persistent, attempting to jog her memory through various means, while the woman remains confounded and elusive, questioning the veracity of his claims.

The narrative unfolds in a surreal, dream-like manner, with the man retelling events of the supposed past encounter, blending reality with possible fiction. Around them, other guests of the chateau engage in idle activities and conversations, contributing to a haunting atmosphere of ambiguity and dislocation. The presence of another man, who may be the woman's husband or lover, adds tension to the interactions between the main characters. The intricate dialogue, the opulent setting, and the mysterious relations create a puzzle that challenges viewers to discern what is real from what might be the product of fantasy or manipulation.