Silver On The Tree: The Dark Is Rising Sequence, Book 5 by Susan Cooper (Paperback)

This is the fifth and last book in "The Dark Is Rising" sequence. The Dark is rising in its last and greatest bid to control the world. The servants of the light: Will Stanton, the last of the Old Ones, the mysterious Professor Merriman, and the strange albino Welsh boy, Bran, are helped by three ordinary children in this last desperate battle.