And Finster never quite emerges as the dangerous entanglement we expect. Still, ''Teeth of the Dog'' delivers, on several levels. Watching an incoming ferryboat, Finster notes the prow ''carving a wedge of foam through the glassy swells. In Vanduuan lore, a boat tugs a whole new ocean behind it. Ocean eats ocean.
New world devours old.
The foam is the mark of its voracious appetite. David Sacks is the author of the Encyclopedia of the Ancient Greek World.