The protagonist orders most of the warriors of the Divine Envoy King's Legion to devote themselves to the construction of the combustion chamber.

The address of the planned combustion chamber is located approximately half a metre north of the nest, which is slightly lower than the entrance to the nest.

The combustion chamber will be located at a depth of three meters underground, with two passages connecting to the combustion chamber from the ground.

A passage is first inclined thirty degrees from the ground, then turned to an angle perpendicular to the horizontal plane, and is connected from the top to the combustion chamber and used as a chimney; The other is tilted forty-five degrees downwards and serves as an inlet for air and fuel.

The space of this combustion chamber is much smaller than that of the regular combustion chamber of "Dongyang Castle", and the four walls are completely disregarded for waterproof design, so the construction difficulty and amount of work are greatly reduced. So, in the second half of the night, the whole project was completed.

There was also a small group of warriors from the Divine Envoy King's legion who were ordered to go to the damp valley in search of the horsetail grass that was common in the region.

Equisetum grass, also known as Qianfeng grass, file grass, pen head grass, pen holder grass, arthropod grass, etc., is a perennial erect herbaceous plant, generally 0.5 to 2 meters high, like to grow in river beaches, streams and other humid places, widely grown in the northern hemisphere temperate zone, subarctic zone.

The main character needs equisetum because the stem is hollow and can be used as a gas pipe. However, the stem of equisetum grass has knots, and the knotted parts are closed. The protagonist needs a horsetail grass about half a meter long, with a total of more than a dozen knots in the middle.

The soldiers of the Divine Envoy King's legion quickly found the appropriate length of horsetail grass, and the soldier ants used large jaws and pottery knives to cut off the horsetail grass, and then the soldiers climbed from both ends into the hollow tunnel of the grass stem with a diameter of half a centimeter, and worked from both ends together, in both directions, using pottery knives and large jaws to open up the joints.

When the work was completed, the soldiers of the King's legion worked together to carry the horsetail grass back to the place of the combustion chamber.

At this time, the combustion chamber has also been completed, and a large number of soldier ants are putting into the combustion chamber the hay, dry moss, thin twigs and other fuels collected nearby.

The protagonist directs the soldiers to insert one end of the horsetail grass pipe diagonally into the chimney mouth, and the joints are pasted with watery clay. The other end of the pipe is inserted into the entrance to the parasitic nest, which is also tightly blocked with wet mud.

In this way, the equisetum pipes connect the chimney mouth to the enemy nest, and the middle part is placed on the ground, covered with a thin layer of sand as a fixation.

After the fuel in the combustion chamber is almost stacked, the protagonist orders a fire, and then asks the soldiers to throw some fresh grass leaves, ant droppings, and peppercorns into the fire.

Fresh grass blades are rich in water and are smoke producing materials like ant droppings. And peppercorns are the secret weapon that the protagonist brings this time extra.

Previously, when the ants were collecting plant seeds, the protagonist found spices such as peppercorns in them. In addition to being used as a seasoning, Sichuan pepper is also a deworming medicine. And the choking smell of peppercorns when burned is comparable to poisonous gas for ants.

After the combustion chamber was ignited, two squads of the Divine Legion were left behind to take turns tending to the fire, replenishing fuel, and generating smoke.

The other teams established a semi-circular defensive position under the huge rock at the exit of the parasitic nest, relying on the terrain, and sent a large number of scouts.

As the fire burns more and more, a large amount of smoke and heat begins to pour into the horsetail grass pipes, and it can be clearly seen that the pipes begin to twist with force in many places, and even the sand covering them is bounced open.

The freshly cut equisetum grass is also rich in water, and it is a whole plant, and it is very well sealed, except for some small smoke leaking out of the wet mud at the two junctions, the rest of the parts are completely leaking.

Although there is a slight air leak at the connection at both ends of the pipe, the connection is very strong, so you don't have to worry about the pipe being washed away by the hot gas. A steady stream of smoke, filled with carbon monoxide, carbon dioxide and choking smoke, is poured into the parasitic nest.

The protagonist waits patiently, and it will take a short time for the poison gas to fill the entire enemy nest.

If, according to the experience of human society, the night is the time when people are asleep, if a sudden fire breaks out and a large amount of toxic smoke quickly spreads throughout the building, the casualties will be extremely heavy.

For example, the apartment building fire in London, England on June 14, 2017, when the fire was fierce and spread rapidly along the building façade, the toxic fumes from the burning of a large number of building materials became the deadliest killer. In the end, the total number of victims of the London apartment building fire disaster reached 79.

However, the most advantageous point of ants in the face of this kind of poisonous gas smoke that appears at night is that even at night, the vast majority of ants do not sleep.

As mentioned earlier, ants are notoriously rare species that fall into deep sleep, and their resting mode is mostly napping.

At present, the protagonist has enforced the rule of sleeping long nights in "Dongyang City", and the result is a significant increase in the average life expectancy of the people of "Dongyang City".

But the parasitic ants obviously don't fall asleep at night, and most of them still run underground, making meaningless energy expenditures.

Since they are not asleep, they will quickly detect the choking gas and take targeted measures.

Whether this response was based on instinct or commanded by a wise man like the Light Gold Worker Ant, what the Divine Legion had to do was crush their attempts at resistance.

Five minutes, ten minutes...... Minutes and seconds passed.

Ants have well-developed sensory organs on their feet that are able to sense the frequency of ground vibrations. The protagonist felt a dense and flustered vibration from the ground beneath his feet a long time ago. Now, the tremors are getting closer and closer to the ground, to the entrances and exits of the parasitic nests.

The equisetum grass pipes that connect the entrances and exits of the parasitic ant nest are still transporting a steady stream of poisonous gases into the enemy's nest, and the damp clay that is used as a seal has been dried and even cracked, and the protagonist has to let the Divine Envoy King's army continue to transport the wet clay, and the connection is constantly strengthened little by little, and finally a hemispherical mud bag is formed larger and larger.

Through the changes in the sensors on his feet, the protagonist seems to see a lot of parasitic ants following the direction of the poisonous gas surge to the original entrance. They may have tried to block the gas pipeline, or they simply wanted to escape to the ground, but under the high concentration of poisonous gas, they collapsed to the ground little by little, and could no longer get up.

The protagonist waits quietly, he thinks that the parasitic ants will not sit still like this, the original entrance and exit is the area with the strongest poisonous gas, and it is unrealistic to reopen the exit from here. However, parasitic ants who are good at digging and burrowing in the soil have the time and ability to open up many other escape routes.

The many scouts of the Divine Envoy King Legion are searching back and forth on the ground of dozens of square meters in the vicinity, and once they find an enemy's escape exit, the Divine Envoy King Legion will rush over and destroy any enemies that appear!