As the straits of the citizens waxed more grievous, secret messengers were sent forth, to implore aid of Sir Francis Vere and of Prince Maurice; but these men never delivered their messages, as was afterwards discovered, and doubtless Volmar had found means to acquaint the Spaniards with their errand, albeit by means that never came to light. Though I kept as good a watch upon him as I could, and my servant did likewise, we could not find him out in aught that would give us a handle against him, and with the passing of time I grew discomfortable in mind, fearing lest Jan Verhoeff’s ten days’ respite should slip away before I had my proofs ready. And I was the more uneasy because I perceived that the ill-will of the burghers towards me increased and spread day by day. Their good favour, which I had at the first procured by my diligence in assisting the defence, had now given place to mistrust and malignity, fostered by Volmar’s minions; and I knew that this canker was eating ever more deeply into the souls of the populace. *VII* On the night of Saturday, a device came into my mind whereby I might bring the truth to light in a manner that could not be gainsaid. It was high time, for a great assembly of the citizens had been holden that day, whereat sundry burghers of good standing openly advised that terms should be made with the enemy. There wanted but three days of the period set by Volmar for the surrender of the city, and on the Monday morning Jan Verhoeff was to die. At this assembly, when I essayed to speak to the people, there arose a great uproar in one quarter of the square, where I perceived certain of Volmar’s creatures to be gathered. Amid the clamour I heard cries of "Spy!" "Traitor!" and sundry other scandalous appellatives; and a stone being cast at me, the Burgomaster commanded me to withdraw out of the throng, lest a general riot should ensue. Therefore, I say, it was high time I did somewhat, and a device came in happy hour into my mind. To perform it I must needs make an accomplice, albeit unwitting, of the Captain of the Guard. He was a man of a most steadfast courage, diligent in his duty, a staunch friend to me, and one that would never yield to the enemy save at the uttermost extremity: a pattern of that loyalty and stubborn valour whereby his nation has won liberty and immortal fame; a man withal simple of soul, as witness his belief in the astrological foolery whereof I have made mention. I resolved to turn this very simplicity to account. I repaired to his house, where he was supping after the fatigues of the day, and after reminding him that the next day was Sunday, I declared that I had discovered a flaw in Mynheer Volmar’s talisman. I affected to have a certain skill in reading the stars, and my study of the heavens had shown me that the customary Sunday truce could only be assured by firing a shot of silver, instead of an iron ball as was wont.