Severino's sickness had extended to his brain.

He was delirious.

This was the first sign.
"Where are you going ?" asked the invalid, querulously, as his companion moved towards the door.
"When was the doctor here last ?" demanded Langholm in return.
There was silence for a few moments, and then a faint laugh, that threatened to break into a sob, from the bed.
"I see what you think.

How can I convince you that I have all my wits about me?
I'd rather not have a light just yet--but in my bag you'll find a writing-case.

It is locked, but the keys are in my trouser's pocket.