“I rejoice to hear it,” said the Emperor, “and do the more readily credit thee inasmuch as a most virtuous and honourable citizen hath already been beforehand with thee, assuring me of the same thing, and affirming that but one traitor, whose name, methinks, sounded like thine, stands between me and the subjugation of Mantua.”

And, withdrawing a curtain, he disclosed the figure of Eustachio.

“I thought he was asleep,” muttered Eustachio.

“That noodle to have been beforehand with me!” murmured Leonardo.

“What perplexes me,” continued Frederick, after enjoying the confusion of the pair for a few moments, “is that our masked friend here will have it that he is the man for the Dukedom, and offers to open the gates to me by a method of his own.”

“By fair fighting, an’ please my liege,” observed the visored personage, “not by these dastardly treacheries.”

“How inhuman!” sighed Eustachio.

“How old-fashioned!” sneered Leonardo.

“The truth is,” continued Frederick, “he gravely doubts whether either of you possesses the influence which you allege, and has devised a method of putting this to the proof, which I trust will commend itself to you.”

Leonardo and Eustachio expressed their readiness to submit their credit with their fellow-citizens to any reasonable trial.