When he emerges, the narrator discovers the Martian has taken all the food from the pantry. For the next several days, he languishes in thirst and hunger, occasionally running the sink even though the water is black. He discovers that the hole in the kitchen wall has been overgrown by the red weed that has accompanied the Martians and spread over the earth. On the fifteenth day, a dog comes into the house and promptly leaves. After hearing the dog walk peacefully away in the garden, the narrator summons the courage to pull back the red weed, and he sees that the pit has been emptied—no Martians or machines are in sight. Venturing outside, the narrator stands on a mound and surveys the land, which has been completely engulfed by the red weed.
That the Martian takes the remainder of the food on its way out of the pantry is significant because it suggests that it knows the narrator is somewhere in the cellar and that he’ll eventually need to eat. This once again proves that the Martians are capable of elaborate cognition and forethought. On another note, the rapid spread of the red weed mirrors the Martians’ quick ascent to power—in the same way that the Martians almost immediately dominate the animal kingdom, the red weed also easily takes dominion over earth’s vegetative ecosystem.