A generation or so after the great bones of dinosaurs had been discovered, men of science became engaged in a frenetic search to uncover more and more specimens of these great beasts who walked the earth uncountable millions of years ago. Two men, in particular, became well-known for their fossil-hunting exploits in the wild west of the 1870s. Their names were Othniel Charles Marsh of Yale University and Edward Drinker Cope from the University of Pennsylvania. They formed and commandeered expeditions into what were then barely inhabited American Indian territories to exhume the fossilized remains of previously unknown species. Between them, they discovered and named more than 130 new dinosaurs. But their scientific fervor also created an intense rivalry between the two paleontologists, which simmered throughout their careers. Both men were obsessed with learning (and stealing) each other's techniques and methods of discovering long buried remains. Timewalker is a bit of alternate history of how Edward Cope may have had some unexpected assistance.