The Walker appears primarily in The Dark is Rising. A scuttling, frightened tramp in Will's time, he is a former friend and servant of Merriman's from the 14th Century, named Hawkin.
Merriman uses him as a security device in the protection of the Book of Gramarye, a risk and responsibility that ultimately he is unable to bear. His resentment drives him into the arms of the witch-girl Maggie Barnes, who tries to recruit him into the Dark. His punishment for listening to her blandishments is to be doomed to carry the Sign of Bronze from his own time, to pass it on to Will 600 years later when the moment comes. Having done so, he again turns from the Light and finds his way into the Dark, who refer to him at least once as The Hawk. He almost destroys Will's quest by calling the Lords of the Dark into a Light stronghold, but is cast down to die by The Rider when he is of no further use to the Dark.