While chasing a Graske in a stolen Time Agent ship, the Doctor and Donna are taken captive by two freed slaves turned bounty hunters in 1850's California. A prize of ten thousand dollars has been levied for the capture of the Time Lord and his companion, but not all is as it seems as their captors, Boss and Amos, befriend the Doctor and Donna. The four then try to figure out the grand scheme of everything, working on who would put up a bounty for their capture, and working out why there is no segregation in pre-Civil War California. The outcome is something straight from the history books, and unlike nothing the Doctor has ever done before. Can he say goodbye to a friend to ensure the prosperity of millions? Why would someone put a bounty on the Doctor and Donna? Well, buy the book and find out.