We rewind back to Sunday and return to the narrator and the curate. When we left our intrepid heroes, they were thinking that something was going to happen with the Martians. Let's look in to see if they're on the money.
After regrouping on Horsell Common to working on something, the Martian tripods go on the offensive.
Some artillery units try to stop the Martians, but things don't go so well for the humans. The narrator gives two examples to demonstrate this: one artillery unit is made up of inexperienced soldiers who panic and run away, while another unit damages (but doesn't destroy) a tripod and then gets blown up by the Martian Heat-Ray.
The narrator wonders if the Martians want to exterminate people. Then leaves us with the parenthetical remark that "At that time no one knew what food they needed," which hopefully creeps you out (1.15.13).
The Martians begin to launch their rockets. The narrator hides with the curate under a bush, but he sneaks out to see what these rockets are. He expects some explosion, but all he sees is some dark cloud (ah, the Black Smoke).
Since the events in this story, the narrator has learned all about the Black Smoke, which is a heavy gas that kills anyone who breathes it. It disperses after a few days (it sinks to the ground and forms a powder coating to the world), unless the Martians get rid of it quicker by spraying steam to clear the air.
In fact, the Black Smoke is so heavy that people who go up high in buildings just might survive.
The narrator and the curate take refuge in an abandoned house in Halliford, waiting out the Black Smoke.
Also, there's a fourth cylinder in Bushey Park.
The Martians advance, using the Black Smoke to kill the army when the guns are hidden, and using their Heat-Ray when the humans' guns are visible.
In the face of that danger, the military basically falls apart. Even sailors mutiny and take their ships out to sea. (This is big news considering what role the navy has played in keeping Britain safe – think of the English navy beating back the Spanish Armada in 1588 or keeping off Napoleon during the Napoleonic Wars.)
The narrator then asks us to imagine what it would feel like to be in one of those artillery units, waiting until you could stop the Martians, but instead being dosed by poison gas. It's not really fun to imagine at all. It's kind of a bummer.
Lastly, the narrator notes that the government, before it disintegrated totally, tried to evacuate London. Which is a nice segue into… Chapter 16: The Exodus from London.