The Door In The Tree (Magician's House Quartet)

Thirteen-year-old William Constant and his two younger sisters, Mary and Alice, have come to ancient, mysterious Golden House in Wales for the holidays. Their lives will never be the same once they enter the Magician's House -- and discover their destiny.

The Secret of Magic

It's vacation again -- time for William, Mary, and Alice to return to Golden House. They've made a solemn vow not to speak of anything that happened on their last visit to Uncle Jack's home. Was the magic real? It seems like a dream to William and Mary. Only Alice knows the secret of magic: believing. It is alice who discovers the Dark and Dreadful Path, Alice who is irresistibly drawn to the ancient yew tree. And it is Alice who finds the door in the tree -- leading to the secret hiding place of the Magician. It wasn't a dream!

Soon they've become the Magician's students, led by the kestel, the badgers, and the dog into the most perilous assignment of all....