Edgar Wallace 
The Strange Countess 
classic

She sat up in bed and a cold shiver ran down her spine. Somebody was in the room! She reached out to turn on the light and could have shrieked, for she touched a hand, a cold, small hand that was resting on the bedside table. For a second she was paralysed and then the hand was suddenly withdrawn. There was a rustle of curtain rings and the momentary glimpse of a figure against the lesser gloom of the night, and, shaking in every limb, she leapt from the bed and switched on the light. The room was empty, but the French window was ajar.

And then she saw on the table by her side, a grey card. Picking it up with shaking hands she read:

“One who loves you, begs you for your life and honour’s sake to leave this house.”

It bore no other signature than a small blue hand …