C R HEDGCOCK
The rock underfoot shuddered, and the faint light that became visible down below jolted crazily.
The glider’s nose caught the air and Phil felt the harness tighten around him. In a moment, the cliff was gone and all their weight hung on the thin, triangular wings. The glider dipped in an accelerating drive, and the brothers took hold of the control bar with their yells whistling past their ears.
When Phil Baker has trouble with an invention he’s building, Detective Mortimer arranges for him to meet a mysterious, brilliant inventor who may the solution. The only catch is that reclusive Sigurd lives in Iceland … in hiding.
Baker Family Adventures, Book 6