1894. A well-respected academic is found dead in a gentlemen's convenience cubicle at the British Museum, the stall locked from the inside. Professor Lance Pickering had been due to give a talk promoting the museum's new "Age of King Arthur" exhibition when he was stabbed repeatedly in the chest. Having forged a strong reputation working alongside the inimitable Inspector Abberline on the Jack the Ripper case, Daniel Wilson is called in to solve the mystery, and he brings his expertise and archaeologist Abigail Fenton with him.