Cryptic Crusade (Douglings Adventures Series Book #3)

The third book in the Douglings Adventures series. 

The Douglas family travels to a wedding in the Colorado mountains, looking forward to a great celebration. But when a close family member is abducted, the eldest children suspect a shadowy figure who has been lurking in the darkness. With the help of their daring and enthusiastic new friend, St. Teresa of Avila, the children will work together to unveil the truth as they enter “The Interior Castle” and infiltrate the dark fortress of their enemy’s very soul.