That Sir Oliver would so speak he could not think.
Indeed, he was entirely assured that Sir Oliver was very far from intending to throw off his burden.

Yet he might come to change his mind.

The burden might grow too heavy, his longings for Rosamund too clamorous, his grief at being in her eyes her brother's murderer too overwhelming.
Lionel's soul shuddered to contemplate the consequences to himself.

His fears were self-revelatory.

He realized how far from sincere had been his proposal that they should tell the truth; he perceived that it had been no more than the emotional outburst of the moment, a proposal which if accepted he must most bitterly have repented.