Strong Bear's Sioux Indians are making noises about breaking the peace treaty. President Grant's first three messengers failed to return from meetings with the Indian leader; now it's up to Jim and Artemus to find Strong Bear and to keep peace in the territory.

West and Pike receive a note to meet a woman at a Chinese restaurant in San Francisco with a promise of information about the militant Din Chang who has recently stolen a supply of fulminate of mercury from a military arsenal. Unfortunately, the woman is killed before they can talk to her and the only word she utters is "Pelican". To further complicate matters, the only person they manage to capture is supposedly still serving time at Alcatraz. Since it seems that Alcatraz and the woman are the two pieces they have of the puzzle, the two split up to track down Chang before he can use the volatile mercury.