I have not made myself sufficiently clear.

The knowledge of that word is a necessity to me.

Without it I cannot complete my plans.

Without it I very much fear, dear Mr.Dunster, that your sojourn among us may be longer than you have any idea of." Mr.Dunster laughed a little derisively.
"We've passed those days," he remarked.

"I've done my best to enter into the humour of this situation, but there are limits.