Mister Midshipman the Alchemist Basil Dumbarton Cathcart arrives at the Shoreston Hill aerodrome, eager to assume his duties aboard His Majesty's Airship Yukon. Unfortunately, he no sooner pays off his taxi driver than enemy fighter-bombers sweep in, low and fast.The enemy’s machine guns spit death, and their bombs shriek down through the keen morning air. The explosions rip up the runways, obliterate the field's fighter aircraft, level critically important buildings, and leave countless personnel dead. The field is crippled, a sitting duck on a millpond.Cathcart must fight back, but how?