Aircraft are being shot down by a large black plane with a big "X" painted on the wing. The chief suspects are invited for the weekend to an old dark mansion.

Planes are being shot down by a large black plane with a large "X" painted on the wing. The chief suspects are invited for the weekend to an old dark mansion.—[email protected]

A mysterious flyer, Pilot X, is a madman whose uncontrollable urge is to shoot down with machine guns commercial airplanes. To capture him and save the reputation of aviation and instill confidence in its safety for passengers and cargo, a transport plane manufacturer enlists the aid of a government agency and a group of five WWI air-ace pilots.—Les Adams <[email protected]>