Word Travelers and the Taj Mahal Mystery

This series by Raj Halder reminds me of Magic Treehouse.  Two kids find a magic book that transports them in time.  But MJ and Edie's magic book is a book of entymology - or the origin of words.  When they travel to India, they learn many of the words they use come from the Indian languages.  They are also helping a new friend follow clues to find a treasure left for his family.  Meanwhile, a dastardly bad guy is also trying to steal it!  (BC HAL)