The Sign on the Hidden Staircase

Part Two of the The Secret of the Red Thread series
A Nancy Drew & Sherlock Holmes mystery

When a terrified heiress arrives at 221B claiming her dead great-aunt is haunting her Victorian mansion, Nancy Drew and Sherlock Holmes uncover a web of family secrets spanning generations. Emma Whitmore's ghostly visitations trace back to wartime Burma, hidden fortunes, and a mechanical puzzle that can only be solved when four become one.

As they navigate secret passages and decode cryptic clues left by a brilliant woman who saw her death coming, a more insidious threat emerges. An unknown blackmailer has been weaponizing innocent moments into potential scandals, sending mysterious packages and threatening messages that strike at the heart of their partnership.

Between haunted mansions and hidden keys, vintage Cobras and viral playlists, Nancy and Sherlock must balance their growing connection against the danger of exposure. Dr. Watson finds himself caught between loyalty and truth, while London's digital sphere notices that Nancy Drew's latest Spotify playlist seems suspiciously specific.

Featuring mechanical mysteries that respond to human hearts, descendants wrestling with their grandfathers' legacy, and enough automotive philosophy to terrorize Baker Street, this second installment asks: What happens when the past refuses to stay buried, and the present is being documented by someone who knows exactly which pressure points to push?

A modern mystery where Victorian secrets meet internet speculation, old friendships transcend death, and two brilliant detectives discover that some puzzles can't be solved with logic alone.
The investigation continues. The blackmailer watches. And somewhere in London, a grandfather clock has started ticking again.