As the poem opens, we're thrown right into the action. A crew of sailors is about to arrive in a new and strange country. When they get there, they find a lazy, tropical place, full of streams and mountains and waterfalls. Pretty soon, they meet the natives, called the "Lotos-eaters," who are a mysterious bunch with "dark faces" (line 26) who look both gentle and sad. Even more importantly, they are carrying some of their favorite food, an "enchanted" plant called the Lotos.
Some of the sailors try the Lotos, and it has a strange effect on them. It makes them incredibly sleepy and lazy. They basically just plop down on the beach and refuse to move, insisting that they are tired of working all the time and want to stay in this new spot and just chill.
The rest of the poem is taken up by the sailors talking about how tired they are, and how, even though they miss their families and their home, it would just be too much work to get back there. Finally they decide to stay forever, relaxing and dreaming and eating Lotos until the day they die. Far out.