"You are quite sure no one else had use of the key except yourself and Kitty?"
"Quite sure, Miss St. Leger."
"And—I am sorry to have to put this question to you, Duane, but under the circumstances I must. You yourself never went inside the laboratory during the time the key was in your possession, and you have no knowledge yourself of anyone who did so, except Kitty Despard?"
"No."
"You give me your word of honour that you have spoken the truth?"
Duane flushed, but replied:
"Yes, Miss St. Leger."
On Kitty's arrival in Eileen's wake, the Principal turned to her.
"I have sent for you to ask you a few questions. The matter is rather a serious one, and I want you to answer me very carefully."
Kitty looked in unmistakable astonishment at the circle of serious faces around her.