Max, a 30-year-old emergency doctor in Berlin, is in a relationship with the possessive Coco. He feels suffocated by her jealousy and longs for freedom. One day, he accidentally dials the wrong number and falls in love with the voice on the other end, who says only "Hello". At night, Max searches the city for the woman behind the voice. He finally meets Marie and her partner Kurt in a billiard salon. After a car accident, Max and Marie have a passionate encounter in the rain. When Max and Coco have a party, Marie and Kurt attend, and Max tries to pair them up.