Silver on the Tree: Susan Cooper

The six servants of the Light - the Drew children, Will, Bran and the mysterious Merriman - have reached their last, desperate fight against the forces of the Dark. They face one final, daunting task: to find the crystal sword. Their search will lead them from their own world to the haunting, magical Lost Land between sea and shore - and they will each stare death in the face before the battle`s final moments.

The fifth and final spellbinding book in the highly acclaimed Dark is Rising sequence.