1) The chapter describes a desolate wasteland called the Valley of Ashes located between West Egg and New York City, covered in dust, smoke, and ashes.
2) In the wasteland stands a billboard with the eyes of Doctor T.J. Eckleburg, which look like they are constantly watching over the area.
3) Nick follows Tom to a small garage in the valley owned by George Wilson, a blond and spiritless man, where they meet George's wife Myrtle and her sister Catherine.