From Cortés, Second Letter, pp. 68-69

The next morning the people [of Cholula] came forth from the city to receive me on the road, with many trumpets and kettle-drums, and a great number of priests, clothed in their customary robes, and singing as they are wont to do in their temples. In this solemn manner they escorted us into the city and assigned us excellent quarters, in which all my people were comfortably lodged. They also supplied us with provisions, though not in a bountiful manner. On the road we fell in with many of those marks of which we had been forewarned by the Tlascaltecas; for we found the royal road blocked up and a new one, opened, and also pits, though not many, and several streets of the city obstructed, and many piles of stones on the tops of the houses. These things placed us more on our guard and led us to exercise greater caution. I met there several envoys of Mocteczuma, who had come to confer with those that had been with me; and they told me that they had only come to ascertain what the others had done and agreed upon, in order that they might return and report to their master. They accordingly departed, after having conferred with their countrymen, and the principal one of those that had been with me returned at the same time. During the three days I was there, they provided very poorly for our wants, and each day worse than the former one; and the nobles and principal men of the city very seldom, came to see or to speak to me. Being somewhat perplexed by this treatment, female interpreter [Malinche] that I had, who was a native of, this country, and whom I obtained at Putunchán on the Rio Grande, (as I have already mentioned in my former dispatch,) was informed by another female, a native of this city, that a numerous force of Mocteczuma lay very near the city, and that the inhabitants had carried out their wives and children and wearing apparel, as an attack was meditated that would destroy us all; and that if she wished to save herself, she should go with her, as she could protect her. My interpreter told this, to Gerónimo de Aguilar, another interpreter, whom I had obtained in Yucatán, of whom I also wrote to your Highness, and he gave me the information; when I took one of the natives of the city, and drew him aside privately so that no one saw me, and interrogated him on the subject; this man confirmed all that the Indian women and the natives of Tlascala had stated. Judging from this information, as well as the signs that I had observed, I determined, to anticipate their movements, in order to prevent being taken by surprise; and sent for the nobles of the city, to whom I said that I wished to speak with them, and shut them in a room by themselves. In the mean time, I caused our people to be put under arms, and ordered them, when a gun was fired as a signal, to attack a crowd of Indians that had collected near my quarters, many of whom had entered within it. After I had shut up the nobles, l left them well secured, and mounting a horse, I caused the signal gun to be fired, and we made such execution that in twp hours more than three thousand of the enemy perished.