A biochemist and his wife arrive in Berlin for a conference in which a scientist and his controversial Arab funder will announce revolutionary research. While his wife checked into the hotel, he takes a taxi to return to the airport to pick up his briefcase, left on the sidewalk. Along the way, a car accident puts him in a coma, from which he wakes up four days later without identification and with gaps in his memory. He goes to the hotel: his wife refuses to recognize him and another man has claimed his identity. With the help of a nurse, the taxi driver, a retired Stasi agent and an academic friend, tries to decipher what is going on. Is the answer in the briefcase.