Book 3 of The Schattenreich

Double Couple begins in Burg Lahn, the ancestral home of the von der Lahn family deep in the hear of the Rhineland, Germany.
Finally reunited, Caitlin Schwarzbach and Hagen von der Lahn, newly returned from his journey deep into the Celtic Otherworld known as Ande-dubnos, seek to pick up the threads of their relationship.
But treachery again thwarts their attempts to return to a semblance of normalcy when someone sets fire to the Burg Lahn woods.
Science takes on the Otherworld when geophysicist Caitlin Schwarzbach strives to unravel the mysteries of the Schattenreich.
But the Schattenreich refuses to cooperate.
Double Couple: a fast-paced supernatural suspense that narrates the story of one woman's journey to overcome her fear, mend a broken heart, and solve the riddle of a 2,000-year old family curse.