His voice had deepened.

It thrilled with a consciousness of irresistible power; it was overwhelming, paralyzing.

His eyes were terrible.
"My men are outside ...

I'm armed," stammered Guerchard.
"Child! Bear in mind ...

bear in mind that it is always when you have foreseen everything, arranged everything, made every combination ...
bear in mind that it is always then that some accident dashes your whole structure to the ground," said the Duke, in the same deep, thrilling voice.