A half-wild, nine-year-old European boy, found wandering with an old Chinese woman in the Indonesian jungle, just might be Brian, the Forrester son thought to have died six years before in a hospital fire. Rather surprisingly, neither Mr. Forrester nor the three other children recognize him, but they are half-committed to taming the cigar-smoking, whisky-thieving urchin who knows no English and much prefers to sleep in the servant quarters. To us at least, the Forresters' life style is as foreign as Brian's: the children commute halfway around the world to British boarding schools and the family at home recreates, with the help of their Asian servants, a mini-England of teas, evening parlor games, and a level of financial anxieties that few could aspire to. When Brian saves the family from a flooding stream he's approvingly judged to have ""good blood,"" and the final discovery that he is, beyond doubt, of Forrester blood seals his acceptance. The boy's civilizing is competently, occasionally touchingly, accomplished, but everything depends on one's willingness to identify with the Forresters' bland, virtually uncrackable self-assurance. Leigh doesn't seem to realize that Donald Forrester, the immaculate prep school head boy, Captain of Cricket, etc., is as much a fantasy as Brian, and a less sympathetic one at that.