Revered as the smartest person alive, Catherine Allingham is the world's most famous private investigator. Stricken with a brain tumor and given six months to live, Cat copes the only way she can - by solving the greatest mystery of all: what happens to us after we die? Collecting the entire critically acclaimed series in one definitive collection, read the epic tale of suspense by Mark Waid, legendary author of the multiple Eisner Award-winning series Kingdom Come and Daredevil , and internationally renowned artist Minck Oosterveer. Featuring an introduction by lauded Wonder Woman writer Gail Simone. Collects The Unknown #1-4, The Unknown: The Devil Within #1-4.