UNIVERSITY lecturer Joe (Daniel Craig) and his sculptor girlfriend Claire (Samantha Morton) are enjoying a picnic in the countryside when they witness a hot air balloon crash-land in a field nearby.

Racing to help, Joe grabs the balloon's basket with four other men, including the pilot, hoping to help the passenger, a terrified boy, jump to safety.

The wind rushes into the field, and the rescuers find themselves airborne.

One by one they drop back to terra firma, but one man - a doctor - holds on too long and plummets to his death.

Joe is understandably traumatised by the experience; so is fellow rescuer Jed Parry (Rhys Ifans), who latches onto Joe for emotional support.

At first, Joe is all too glad to talk to Jed to help him deal with his shock and guilt. But as the stranger's interest in the lecturer intensifies, Joe realises that he is the object of a dangerous obsession.