This young reader novel begins with a high school field trip to the former gold rush town of Yale in British Columbia. Here Zach, Kyle, and their eccentric teacher, Miss Reid, are transported back in time to 1866 at the height of the Cariboo gold rush. Stranded in Yale, the threesome are taken under the wing of Theo Cox, who becomes their friend and persuades his brother Enos, who is carrying freight in his wagon to Barkerville, to take the three along with them. It is an arduous and at times dangerous journey on a road hastily built to accommodate the throng of people seeking riches in the Cariboo. Once they reach the famous gold-mining town, it is hoped they can find work to survive. Barkerville presents many hardships and also many exotic adventures for the trio from the 21st century. But a murder has been committed, and the evidence seems to point to their friend Theo. Soon Theo finds himself fighting for his life at a trial presided over by the imposing and straight-talking Judge Begbie. Desperate, Zach intercedes with the famously severe judge to find a way to save Theo from the gallows.