Ben Jeapes 
Time’s Chariot [EPUB ebook] 

His last thought, as the stun charges lanced through him and he felt his body arch and then start its slow, dreamlike tumble down the stairs, was:What did I do wrong? Rico Garron is in trouble — again. What starts out as a routine expedition back to five thousand BC, turns into the first murder investigation for hundreds of years. A complex spiral of subterfuge, intrigue and powerplay begins to unravel, and now the entire future of the world is at stake . . .