The Saint investigates a racket in which illegal immigrants are smuggled into Britain.A fishing expedition produces an unusual haul for Simon Templar, the Saint (ROGER MOORE), when his boat is almost run down in thick fog and he hears a shot, abody being thrown overboard, and drags a murder victim out of the water.He has sailed into a grim smuggling racket - the illegal importing of immigrants into Britain. The men responsible are Bonner (NEIL HALLETT) and Slater (GARY MILLER).In the local Yacht Club, the Saint drifts into conversation with an attractive girl named Laura (SUSAN TRAVERS), who is waiting for Bonner.When Bonner arrives, he apologises for having to leave Laura to her own devices because of an urgent message, and she accepts the Saint's invitation to drive her up to London.Meanwhile, Bonner is forced to take his latest cargo to London himself because Slater has had trouble with the police and has lost one or two of the Pakistaniimmigrants. As this is happening, the Saint is questioning Laura about her man-friend, and he learns that Bonner is a boat-broker who hasn't sold a boat in months - but still seems to be making money.But Banner is also facing financial problems because he is being blackmailed by Slater. The Saint, more than ever convinced that Bonner has something to do with the shooting he has overheard, follows a trail which leads him to the clearing-house used by Bonner, where he finds a very ill Pakistani named Chaudri (NIK ZARAN), who rejects the Saint's offer to take him to a doctor. Before the Saint can take further action, Chaudri is shot, and when the Saint escapes and returns with a doctor it is discovered (I-) that the Pakistani had smallpox. The hunt is then on for the other Pakistanis who are potential carriers. And Bonner himself is hunting for a lovely model, Nana Gupta (InCGEN HASSALL), who can lead him to her brother Suresh (SALMAAN PEER), who intends to give the authorities details of the illegal 'peo watch