In Book 3 of the Penumbra series, assassins target Captain Ben Lamont and his co-pilot after they've been asked to investigate a new wormhole. More determined than ever, Lamont sets out with his crew to learn what they're not supposed to discover there. Along the way, they find the smoldering remains of a colony and come under fire from unknown assailants. Can Lamont and the crew of Penumbra uncover the secret that has caused so much death and destruction? And will one of their own pay the ultimate price to expose the truth?