Paradox: On the Sharp Edge of the Blade. The Time Equation Novels, #2

SOMETIMES A PARADOX IN TIME CAN BE A GOOD THING Logan Walker must graduate from college in four years to fulfill the terms of the trust that controls his inheritance. It's almost too late when he realizes he shouldn't have spent so much time playing computer games. His last-minute attempt to earn the required credit hours takes an unexpected wrong turn, resulting in an archaeological discovery that may ruin his chance to graduate on time.  Life becomes even more complicated when he accidentally displaces himself in time.
The fierce animals and lack of civilization lead him to conclude he's in the Ice Age. He must adapt to a cruel world where losing is permanent and there is no replay.  His survival hinges on the goodwill of a mysterious girl who is running from her own problems. Together, the two encounter enemy tribesmen and fierce animals. Logan's understanding of life quickly changes as he faces one challenge after another. The girl comes and goes in his life, even though he'd much rather have her near.
His desire to be with her leads him into a series of battles and increasingly desperate acts. He finds the intermittent presence of a fox that seems to be trailing him poor consolation for her absence. Will his new attitude allow him to face his adversaries and avoid death? Will he defeat his most powerful enemy: Time itself?