There's  a storm brewing and I'm cuddled on the couch completely mesmerized by Susan Cooper's Over Sea Under Stone, the first book in her The Dark is Rising series.  The copyright is 1965, so for some readers this might be considered too out-of-date to be considered for inclusion in their library.  Please don't be so hasty in your thinking.  I love this series of five books...from the first time I discovered it I've been a serious Cooper fan.  First, this is truly an adventure story built around three children, Simon, Jane, and Barney and their mysterious Great Uncle Merry.  Arthurian legends are cleverly woven in the tale of dark vs light, good vs evil where the lines are not always so clearly drawn and a human element is always present.  The race is on to decipher the signs "that wax and wane but do not die" leading to grail, a source of power to fight the powers of the Dark.  The setting is Cornwall and the small fishing village of Trewissick with its secrets kept for over 900 years.  The characters are familiar and bicker as all siblings do and yet pull together to solve a mystery larger than time and legend.  The forces of evil are clear cut and yet there are a few surprises as well, because as long as the Light and Dark has existed men will continue to be swayed toward the false promises of evil.  And it is those complex relationships that remain fresh and contemporary and totally relevant for today.  The layers of setting, characters, plot, and suspense make The Dark is Rising a series I turn to again and again to be entertained, mystified, and awed by the skillful weaving of history, legend, and man's continuing inner battle of Light and Dark.  
Visit Susan Cooper's website at: http://www.thelostland.com/
Visit Susan Cooper's website at: http://www.thelostland.com/