Wind Raker - Book Four of the Order of the Air. The Order of the Air, #5

A Deadly ParadiseIt's the summer of 1935, and Gilchrist Aviation's owner Alma Gilchrist Segura has brokered a deal that will take herself and fellow pilots Lewis Segura and Mitchell Sorley to Honolulu to test a new seaplane. It pays well enough to take their families along for a working vacation - including the children of the company's part time handyman, whose father has abandoned them. Better still, archeologist Jerry Ballard is already there supervising a dig investigating whether Hawaii was actually discovered by the Chinese.
It's a crackpot idea, but it's his only chance to prove that he can still handle field work after losing his leg at the end of the Great War, and he's determined to restart his career. However, not all is as it seems. The dig is funded by anonymous sources who seem to have far too much influence on its management, including the hiring of German archaeologist Willi Radke, and who seem to know exactly what they want to find.
The seaplane's testing is plagued by mysterious mechanical problems - and rumors of a curse spread through the hangar. Can you murder someone by magic? And who would want to kill a middle aged Army officer who belongs to an allied lodge? Alma, Jerry, Mitch, Lewis and Stasi are determined to defend themselves, but the power arrayed against them is greater than they imagined. It will take everything they have - as flyers, scholars, and magicians - to survive this deadly paradise.