Book I, Chapter 9: "At the Sign of the Prancing Pony"
Bree-land is a region just east of the Shire, populated by both Hobbits and Men (the term refers to human beings as opposed to Hobbits, Dwarves, etc., throughout The Lord of the Rings, and should not be taken as gender-specific when capitalized). The "Little Folk" and "Big Folk," however, do not usually have dealings with each other. As a result, the gatekeeper at the village of Bree greets four Hobbits-from the Shire, no less-with surprise. The gatekeeper does not see a Black Rider climbing into the village behind the travelers.
At the Prancing Pony, innkeeper Barliman Butterbur tells the newcomers that their arrival reminds him of something, but he does not know what. The Hobbits socialize with other travelers in the inn's common room, although Frodo tries to keep to himself. He is disturbed by the presence of "a strange-looking weather-beaten man" who sits in a corner alone, intently watching Frodo. Butterbur introduces Frodo the man, who is a Ranger called "Strider." Strider seems to know that "Underhill" is not Frodo's true name, and also warns him to stop his friends from talking too freely. Indeed, at that moment, Pippin is relating the story of Bilbo's sudden disappearance. To create a distraction, Frodo-again resisting the temptation to wear the Ring-sings a song and dances on a table. He slips, falls, and vanishes from sight. "How [the Ring] came to be on his finger he could not tell"-whether by his own accidental handling of it, or by the Ring's own will. When Frodo reappears, Strider reveals that he knows the Hobbit's true name, and tells Frodo that the two of them must talk.