Lloyd Walker is an anti-heroic archaeologist who, after stumbling upon an alien conspiracy, becomes enmeshed in an against-all-odds battle to save the human race. From the enigmatic Room 86 to the doomed Pericles space mission, Walker puzzles together clues to reveal the dark purpose behind strange events occurring around San Francisco. Now, the "keeper of dead civilizations" must rescue mankind from slavery at the hands of some very big, very terrifying insect-aliens..