Lord of the Ring Chapter 3

A Black Rider also known as a ring wraith 

    In chapter 3, Frodo finally decides to leave on his journey in the autumn after his and Bilbo's birthday party. This is good because so far he has just procrastinated, so some dark and evil thing is already after him and the ring. In the Shire there is news of many different creatures that have not stirred for a long time wandering around the outskirts of the Shire. I think this should be called the great stirring because creatures are stirring. Frodo sells Bag End to the Sackville- Bagginses and bought a house in Crickhollow at Bucklebury and pretends that he will settle down there except to Sam who will be accompanying him. I think that this is mischievous, just like Bilbo. When he finally sets off, Pippin comes with him and Sam to Crickhollow. When three Black Riders come across their path at different times,and sniff the air looking for Frodo I know that trouble has already risen with the knowledge of Frodo's ring. I predict that these Black Riders are going to cause trouble later on in the book. They are going through open roads when another Black Rider comes from behind them. They hide in the bushes next to the road and then elves come up the road singing, scaring the Black Rider away. This is good because I think the Black Rider was just about to discover the hobbit's hiding place. When they come out to greet and thank the elves, the elves immediately accepted them into their group because of Frodo's ability to speak their language. The elves lead them to an open place in the woods to rest for the night. The elves provide them with a good dinner and then Frodo and Gildor, the elves leader, talk for a long time. I think Frodo will learn a lot but will not be sure what to do with the knowledge.Gildor knows where and why Frodo is going, and in the end he tells him to beware of the danger that lies ahead of him. In the morning the elves are gone but the knowledge Frodo collected is not. I want to know who are the Black Riders and why do they need Frodo so badly?