Probability Sun [signed] [signed] [first edition]

Salvation or Annihilation?A strange artifact has been discovered on a distant planet, an artifact that may be the key to humanity's salvation. For we at war with the Fallers, an alien race bent on nothing short of genocide, and this is a war we are losing. The artifact is not only a powerful weapon, but possibly the rosetta stone to a lost superscience . . . a superscience that the Fallers may have already decoded. Or it may be a doomsday machine that could destroy the very fabric of space.