1817. Clemency van Emden receives an anonymous terse message informing her that her estranged father is dead and buried. A chance encounter on a busy London street leads her to twin detectives Peter and Paul Skillen, who agree to help her unravel the mystery of her father's last days.
However, Paul's attention is diverted away from London to Bath, as he seeks to thwart a daring band of highwaymen, one of whom appears to have more than just jewels on his mind. When the body of Clemency's father is discovered to be missing from its casket, the twins embark on a chase of graverobbers, funerary agents and Good Samaritans to unearth the truth.