Gandalf's Pursuit of Frodo and the Nazgûl

Gandalf arrived at Frodo's new home in Crickhollow, Bag End having been sold to the Sackville-Bagginses. However, he found the house forcibly opened and empty. Frodo's coat was left on the doorstep, raising concerns. Gandalf suspected the Nazgûl had invaded the house and might have captured Frodo, taking the Ring. He lost hope and imagined they might have already taken Frodo.

Gandalf mounted Shadowfax and swiftly rode in pursuit, like the wind. However, tracking them proved challenging as they took various paths and scattered. He passed through Bree, where he learned from Barliman Butterbur that Frodo, accompanied by Strider, had left with a company.

The next morning, Gandalf rode to Weathertop. The Black Riders were there before him but withdrew, sensing his wrath. A fiery confrontation ensued in the ancient ruins of Amon Sûl, described as an intense battle of flames and light, harking back to the old days of Amon Sûl's glory.

After driving off the Nazgûl, Gandalf fled towards Rivendell with the rising sun. Four of the Nazgûl followed him briefly but eventually turned back. This helped Frodo, as when they attacked his camp atop the hill, there were only five Nazgûl instead of the full nine.

Gandalf's pursuit and clash with the Nazgûl played a crucial role in Frodo's safety during his journey to Rivendell.