"In the Company of Thieves" by Kage Baker

Do you want a jewel worn by Cleopatra, an original Shakespeare folio, or the combined genes of Socrates and Marilyn Monroe? Dr. Zeus can make your dreams come true.

The Company, a powerful corporate entity in the twenty-fourth century, has discovered a nearly foolproof recipe for success: immortal employees and time travel. It specializes in retrieving extraordinary treasures out of the past, gathered by cybernetically enhanced workers who pass as ordinary people. Or at least they try to pass....

One rule at Dr. Zeus Incorporated must not be broken: Recorded history cannot be changed. But avoiding the attention of mortals while stealing from them? It’s definitely not in the Company manual.

History awaits, although not quite the one you remember.