He learned from Urrea that Houston would arrive in a day or two with more volunteers from Eastern Texas, and the young Mexican also told him something about San Antonio.
"Cos has a large force of regular troops," he said, "but he is alarmed.
He did not think that the Texans were in such earnest, and that they would dare so much.

Now, he is barricading the streets and building breastworks." The Texans were so resolute and confident that the next day they sent a demand to Cos for his surrender.

He would not receive it, and threatened that if another white flag appeared he would fire upon it.

A day or two later, Houston and the Eastern Texans arrived, and Ned, Obed, the Ring Tailed Panther and Urrea planned a daring adventure for the following night.

They had heard how Cos was fortifying San Antonio, and as they expected the Texan army to make an assault they intended to see just what he was doing.
They made their way very cautiously toward the town, left on foot when the full dark had come.