[Inziladun]

I quite like The Shadow of the Past.

Gandalf's dark exposition to Frodo at Bag End, the most peaceful, pleasant locale for it, makes his words that much more jarring. It's like sudden thunderheads on a day that had been sunny.

Also, The Old Forest and Fog On the Barrow-Downs, in a similar vein, start to physically immerse the reader, with the innocent hobbits, in the wider, more dangerous world outside the Shire.