[akhtene]

I hape I won't be greatly mistaken if I say this chapter is #1 in a way. To me "The Long Expected Party" looks kind of link between "The Hobbit" and LOTR, a good-bye to Bilbo as the main character.
But "The shadow..." starts an altogether new story. It's there that we get to know Frodo NOT JUST as Bilbo's nephew.It's there that we learn the true story of the Ring - not in the first chapter, as it doesn't really concern Bilbo or the events of "The Hobbit". And there plans for the future are made.
So, the past, present and future come together in it. THE PAST - the story of the Ring and of Gollum. THE PRESENT - the hobbit rumours of what's going on 'in the world':strange wonderers, elves leaving for the West... The FUTURE - the necessity to dispose of the Ring, and 3 members of the Fellowship already together.
And different styles of writing we can come across too. The solemn and a bit scary story of the Ring. A matter-of-fact, but so 'cosy' description of Frodo's life. Soft humour in the scene of 'capturing' Sam (most sutable at the end of this grim chapter)
Thus, in a sense, it introduces the book.