At last, Tabitha and Wolf can relax and settle into newlywed bliss... or so they think.

Just as they prepare to leave London for a quiet summer at the Pembroke Estate, an unexpected—and rather cryptic—invitation arrives. The notoriously flamboyant Henry Cyril Paget, 5th Marquess of Anglesey, has personally requested their presence at Plas Newydd, his ancestral estate, accompanied by a desperate plea for their investigative skills. Intrigued, the couple agrees to a detour—with the ever-formidable dowager in tow, of course.

But upon their arrival, it's not just the marquess's lavish theatrics and eccentric indulgences that catch them off guard. Another guest is in residence—none other than Empress Elisabeth of Austria, "Sisi" herself, who has taken refuge at Plas Newydd after receiving chilling threats against her life.

Now, Tabitha and Wolf must unravel the danger that lurks within the marquess's gilded world—before their most illustrious charge becomes its next victim.