Prot is back and patient Robert has returned to catatonia at the Manhattan Institute. This visit to EARTH, prot promises, will be his very last and so Dr. Gene Brewer has limited and precious time in which to unravel the mystery of prot and recall Robert to life. But around him excitement turns to hysteria as prot's charm and influence on the other patients and on the world exerts itself. Prot will be taking one hundred beings with him when he leaves, to live on the perfect planet K-PAX, and everybody is clamouring to be chosen. Will prot's true identity be revealed, and will Dr. Gene be left wondering for ever?