Through an "accident" the crew gets shot 300 years back in time. They find themselves at the battleground of a pivitol battle between the neitchiens and Commonwealth.
Aside from the normal question of fate this raises (and it raises a few) the really good part is the characterization.
Every character has their own agenda and point of view.
Trance - She seems to know much more than she let on. It's more than possible that she arranged the trip back in time.
Dylan - Sees his opprotunity to help save the Commonwealth, or at least a friend.
Rommie - as a warship wants to stand and fight.
Harper - Attempts to kill the neitchien fleet and make himself a historical hero.
Tyr - tries to convince Dylan to help the neitchiens, thereby letting the neitchiens rule eath rather than let it be devoured by the magog. He even threatens Trance in one very good scene.
This is one of the best time travel stories which are very hard to pull off (Voyager, anyone?) but RHW manages to do it well, making this a classic.
