The poet Paul Muldoon cupped his hands around his mouth and set his eyes on the ground. He let out a big coyote howl as he walked up the path to Robert Frost's summer cabin, now his. He wanted to let the bears know he was coming. The cabin is buried behind trees and made of dull brown wood, fading to gray. On the porch, Mr. Muldoon struggled with the lock on the green door for a moment, and then we entered. Inside it smelled like 100-year-old wood. At the window by the phone--the same phone Frost used to call Homer Noble Farm, a stone's throw from the cabin, where his secretary, Kate Morrison, lived with her husband, Theodore--Mr. Muldoon looked out across the field where he likes to practice shooting his bow and arrow. Frost spent 24 summers on the farm; this is Mr. Muldoon's 13th.