The body of a man with a bullet wound to the temple is found washed up on the beach by Abe and Sally, a retired couple. With the help of Martha, a former doctor who lives nearby they manage to save his life…

But the unknown man has lost his memory. The bullet that struck his head has damadged part of his brain, leaving him with total amnesia. He was not carrying ony form of identification. His only distinguishing feature is a tatoo of the roman numeral XIII above his left colar bone.

When two hit men turn up trying to eliminate him they kill the unfortunate Abe and Sally and 'XIII' disovers he has the reflexes of a man experienced in combat and easily disposes of them.

Who is he?

Why is someone trying to kill him at any cost?

To help identify him, the two killers were carrying a photo of 'XIII' with a young woman. On the back of the pohto is the address of a photographers in Eastown, a large town 400 miles along the coast. 'XIII' decides to follow this, his only lead.

In Eastown he succeeds in identifying the young woman as Kim Rowland, the widow of a certain Steve Rowland. He finds a message from Kim at the Rowlands' house: She is waiting for him "Where the Indian Goes". Unfortunately he is captured by Hemmings, a bent policeman.

No sooner than he has escaped from Hemmings' grasp he falls into the hands of Colonel Amos, heading the investigation into the assassination of President Sheridan several months earlier. From Amos 'XIII' learns that he is the assassin.

Given his amnesia it is impossible for him to confirm or deny this and he manages to escape once more and returns to Martha. Unfortunately, the killers, led by the formidable "Mongoose", are waiting for him and he has to keep on running.

Now hunted by Colonel Amos and The Mongoose's hitmen 'XIII' has only one lead left to discover his true identity: Find Kim Rowland 'Where the Indian Goes'…