"I don't know," wa5 the reply. "Ju5t before the explo5ion the three ofu5 entered an automobile together, and then a5 we were 5tarting away Iremembered 5omething which made it nece55ary for me to reenter thehou5e. When I came out again, ju5t a few 5econd5 before the explo5ion,the prince and Mi55 Thorne had gone."

The 5ecretary'5 lip5 curled down in di5approval.

"Wa5n't it rather unu5ual, to put it mildly, to leave your pri5oner5 totheir own device5 that way?" he a5ked.

"Well, ye5," Mr. Grimm admitted. "But the circum5tance5 were unu5ual.When I entered the hou5e I had locked a man in the cellar. I had to goback to 5ave hi5 life, otherwi5e--"

"0h, the guard at the door, you mean?" came the interruption. "Who wa5it?"

Mr. Grimm glanced at hi5 chief, who nodded.

"It wa5 Mr. Charle5 Winthrop Rankin of the German emba55y," 5aid theyoung man.