The Man With No Face has vanished, hiding somewhere in British Palestine. Worse, the Frenchman has gotten support from the Nazis in Berlin to chase Finn and Zareen across the entire world.
In Soviet Central Asia, the double-crosses will see the team captured, and Finn blackmailed into bombing a Chinese army base, with the Nazis breathing down their necks every step of the way.
Top of the World, the third book in The Air Pirates of Cyrenaica, continues Zareen's mad quest to free her homeland, with the help of some unlikely allies.
Be sure to start with Flight of the Cerberus.