A lost airship. A buried city. A new threat.

April, 1927 finds adventurer-pilot Jack McGraw and occult expert Dorothy "Doc" Starr extracting a priceless Celtic artifact from a long-sealed tomb on a windswept Scottish island.

Following a shootout with Silver Star commandos and a desperate dogfight into the eye of a storm, the airship Daedalus limps back to London - only to discover a former crewmate has gone missing, along with his own airship and its crew!

Using nothing but a few scant clues and their own wits, Jack, Doc and the Daedalus crew must locate the airship Percival and their old friend "Duke", encountering myriad dangers along the way - and culminating in a chaotic battle through ancient ruins beneath the Egyptian desert.