Are you sure you haven't seen Torchwood? Because that IS what it's about. *nods*

Also, have you ever read any of Kage Baker's "Company" series? Immortal cyborgs who rescue things that were lost in the past. Lost books and plays and plants and things. The first one is "The Garden of Iden," yes, bad pun, sorry, and you can kind of tell it was her first book, but it's still entertaining and they get better (and more complicated) fast.