The A.A. Western Detective Agency takes on a new case in 1894 Wyoming, a land of bandit gangs and rustlers, when a group of scientists come to town in the hopes of rustling up something very different-dinosaur fossils.

With Big Red and Old Red Amlingmeyer on protection duty, Old Red's obsession with Sherlock Holmes is forced to take a back seat. Until a human body is shockingly discovered during an excavation, that is.

As the mystery deepens, these cowboy detectives must put their sleuthing skills to the test to catch a killer stalking their client's dig site.

With death lurking around every corner, can the Double-A Western Detective Agency catch the killer before it's too late?