A collection of 10 short stories about an organisation that polices the timelines, making sure that history is not altered by renegade time-travellers.
The good: vivid evocation of far-flung time and places, a great sense of how history works, an interesting take on time-travel paradoxes and Anderson's usual large-scale vision of past, present and future, as well as unobtrusively vivid prose and instinct for heroic pathos.
The bad: Basic plots are repetitive, so you can't read too many at one go. Too many firm-jawed manly men and winsome wenches waiting to be won; deeply antediluvian gender politics, in other words. But still not as bad as Heinlein's sexy sexism.