Edith Nesbit 
The House of Arden [EPUB ebook] 

With the Arden family castle in ruins and the family treasure lost for generations, Edred Arden is graced with the chance of a lifetime just prior to his tenth birthday. When he inherits the title of Lord he discovers that if he can find the lost family treasure before he turns ten, it will be his. With his sister Elfrida at his side, Edred sets out on a magical time-travelling quest to restore the House of Arden to its former glory. Fans of Edith Nesbit will delight in this wonderful children’s story of fantastical adventure.