Rumors swirl that the sabotage of Tesla's aether towers can be laid at the feet of the mysterious Elf King. King Edward's Secret Service calls out Dougray Cameron to investigate the tower in northern Ireland, and his wife Kate secretly follows him. When the tower collapses Kate is there, and sees Doug plummet into the icy surf below.

In her horror she realizes the gentleman next to her applauded the collapse – and now he's vanished! Surely he had a hand in the tower's collapse, surely he killed Doug, and surely Kate will make Errol Koenig pay.

She chases him across the waters to Paris, then on to Constantinople and beyond. Along the way she's aided by Winston Churchill, P. G. Wodehouse, Mata Hari, Arsène Lupin, and Nicola Tesla.

Despite relentless pursuit, somehow the moment for the fatal blow never arrives. Is it Errol Koenig's strange allure that stays her hand? Does he truly have powers modern science cannot explain? And are his whispers that Dougray survived, and awaits his Kate during recuperation, true?

Understanding comes when Kate is drawn into a life-or-death duel between wizards atop an ancient castle in a roaring storm (I know!).