ten o'clock
`` There is still the writing , '' suggested Gladys , turning over the other photograph . `` That , '' said Mr. Ardmore , after a moment 's study of it , `` is written in some strange tongue and is , I take it , unintelligible to us all . '' `` It 's a photograph of the back of the map , '' suggested Curlie , pointing out certain spots where the wrinkles and tears were the same . `` My French teacher will be here at ten o'clock . He knows several languages . Perhaps he could help us , '' suggested Gladys . `` We will leave that to him , '' said her father .