Get two cover books appropriate for teen readers and older.

 A Rather Lovely Inheritance by CA Belmond - This is the first book in the Penny Nichols Series.  After her Aunt Penelope dies, historical researcher Penny Nichols is astonished to learn that not only is she a bona fide heiress-but she's also been invited to put her research skills to work. This time, the history she's researching happens to be her very own. 

The Midnight Palace by Carlos Ruiz Zafón - Set in Calcutta in the 1930s, The Midnight Palace begins on a dark night when an English lieutenant fights to save newborn twins Ben and Sheere from an unthinkable threat. Despite monsoon-force rains and terrible danger lurking around every street corner, the young lieutenant manages to get them to safety, but not without losing his own life. . . .

Years later, on the eve of Ben and Sheere's sixteenth birthday, the mysterious threat reenters their lives. This time, it may be impossible to escape. With the help of their brave friends, the twins will have to take a stand against the terror that watches them in the shadows of the night—and face the most frightening creature in the history of the City of Palaces.