"He committed an error, that is all.

Let him at least have the privilege of making his own explanations.

I will add to my letter that only for a week longer can I keep his secret, and, to make an immediate revelation imperative on him, will say that you know all, and will reveal all at the end of that time, if he does not." No considerations that Mrs.Markland could urge had any effect to change the purpose of Fanny in this matter.
"I must hold you to your promise," was the brief, final answer to every argument set forth by her mother.
How far she might hold that promise sacred was a subject of long and grave debate in the mind of Mrs.Markland.But we will not here anticipate her decision..