"This surprise attack, Luo Zheng arranged for men to block the pursuing Japanese pirates and first release Poison Smoke, which only produced a flame and no noise, so it wouldn't alert the people underground. The patrolling men who came to investigate were overwhelmed by the Poison Smoke. Once that was mostly done, logs and Poison Smoke were released together to increase the potency and spread of the smoke. The logs also triggered Land Mines to ignite the forest and clear out the last obstacles for the assault.