She knew that if she presented herself before her father sound and whole, she would at once be placed under some close restraint that would effectually hinder her from carrying out her plan.

He would sooner kill her, as she verily believed, than permit her such liberty as might enable her to meet by accident or design any member of the household from the Chase.
If she were to succeed in her escape, the attempt must be made whilst her father still believed her too feeble to stir from her bed; after that she would be too closely watched for it to be possible.
The old woman entered into this scheme with alacrity and zeal.
Petronella kept to her bed; and when Nicholas Trevlyn demanded by signs how it fared with his daughter, he was answered by solemn shakings of the head.

If he mounted the stairs to see with his own eyes how she was, he saw her lying upon the bed with closed eyes and wan face, and would smile with an evil smile and mutter that she was safe enough now--safe enough now.
Yet each day hope and the good food the shrewd old woman contrived to provide for her did its work upon Petronella's frail body, and she grew better every hour.

Indeed, after some while she felt stronger than she had done for many weeks before her illness; and in due time even the fond old woman began to see that there was no need to postpone longer the scheme of escape.
It was a simple little scheme, yet one which promised success if carefully carried out.

Nicholas Trevlyn was accustomed to take night by night a posset of mead, brewed in some particular way by Martha.