A Marine major (Pat O'Brien) looks out for his captain (Robert Ryan) on Guadalcanal and in Australia. A Marine major (Pat O'Brien) looks out for his captain (Robert Ryan) on Guadalcanal and in Australia. A Marine major (Pat O'Brien) looks out for his captain (Robert Ryan) on Guadalcanal and in Australia. A Marine major (Pat O'Brien) looks out for his captain (Robert Ryan) on Guadalcanal and in Australia.