The door to Bag End deliquesced, and the derelict lurched into the hall.
He was an old man. He was a strong man. Must be Gandalf, Frodo thought. Dresses like Gandalf, grey robed, a rope holding up his torn grey pants. And his eyes. (Orcs' eyes?).
"You , boy. Are you Frodo Baggins?"
Frodo fingered the dirt between his hairy toes. Wanting to say "no" he began a "yes".
The codger flapped out a hand (a sack of magic-ruined knuckles) and caught a chair. "We were moving out, boy, the lights of Minas Tirith like a puddle of molten mithril on our left, the black of Mordor on our right. We'd turned off the palantir so we were flying blind. Then, centred on the dark, an Eye! It reached out, brighter than the elven-glass of Galadriel, grabbed our attention so we couldn't look away."
Frodo got the words ready in his mouth, excuse me, huh? I gotta go.
Gandalf coughed, spat red. "The Eye was Sauron's. He took us this close" - his thumb brushed his forefinger (nail bitten to the quick) - "this close" - to Mount Doom. You can damn him, and damn the One Ring for that, boy, whoever you are!"