The novel “Peacemaker” by James Swallow was published for the first time in 2007.

Two guys on horseback reach a normal farm in the Far West and demand that the owner tells them where they can find a mysterious healer. When the man refuses to help them and tries to send them away they kill him using energy weapons and resume their search.

Martha Jones would like to see a western movie but the Tenth Doctor takes her to the real old West, in the town of Redwater. Shortly before, many people in the area were ill with smallpox and risked dying, but a passing physician healed them. He looks like one of the many scammers that existed at that time, but his medicine worked, the problem is that the people who got healed have strange dreams.