Allured by the prospect of spoils, the Chinampanec crews arranged a plan whereby a still richer draught might be made. Before their adhesion to the Spanish cause, or knowledge of it had yet come to Quauhtemotzin, they sent to offer him their services against the invaders, with whom they proposed to deal treacherously. They were assigned a post and played their part well. No sooner were the Mexicans occupied with the Spanish forces than they rushed
into the dwellings of their pretended allies and began to rob, slay, and carry off women and children. An alarm was given and reënforcements hurried up which speedily overwhelmed the traitorous crews, killing a number, capturing others, and recovering nearly all the booty. The captives were condemned to the stone of sacrifice, those of Cuitlahuac by one of their own caciques, Mayehuatzin, a companion of Quauhtemotzin. The incident cost many lives on both sides, greatly to the delight of the Spaniards, to whom this mutual throat-cutting was the economy of war.8
With so large a hostile fleet upon the lake the Mexican crews never ventured abroad by day, but when darkness set in, their canoes sped across, impelled by the demand for food. Informed of this, Cortés detached two brigantines, under Portillo and Pedro Barba, to cruise all night. This proved a severe blow to the poor Mexicans, although a number of canoes still ran the blockade successfully, and it was resolved to entrap the vessels, since open battle could not avail against them. Thirty of the largest canoes, or piraguas, were accordingly manned with stout warriors and strong boatmen, and hidden amongst the rushes near a heavily staked channel, into which some swift canoes were to decoy the brigantines. This succeeded, and no sooner were they fast on the stakes than the canoes attacked them with such spirit that every Spaniard was wounded, while Portillo fell, and Barba died within three days.9 The brigantines managed to escape. Encouraged by this attempt the Mexicans became more brisk in their blockade-running, and stationed forty piraguas to repeat