Trust nobody.

Be careful.
I can say no more." "He means Uncle Stanley," thought Mary, uneasily, and a shadow fell upon the day.

She was still troubled when another disturbing incident arose.
"I'll leave these papers in the desk here," she thought, taking her keys from her handbag.

She unlocked the top drawer and was about to place the papers on top of those which already lay there, when suddenly she paused and her eyes opened wide.
On the top letter in her drawer--a grey tinted sheet--was a scattered mound of cigarette ash.
"Somebody's been here--snooping," she thought.

"Somebody with a key to the desk.