The Asylum, London

A private asylum where Sir Percival Glyde unjustly locks up Anne Catherick to keep her from revealing his secret. Though it is eventually revealed that she never knew the secret, the punishment draws attention to the secret so that it is later revealed. Hence, Sir Percival's wicked action leads to his undoing. Later in the story, Laura Fairlie (Lady Glyde) is locked up in the same asylum under the name of her look-alike half-sister, Anne Catherick. Laura is rescued by her other half-sister, Marian Halcombe.

Blackwater Park, Hampshire

The creaking, ancient home has one wing in disrepair and the rest is maintained by a scant staff of servants. Nearby is a stagnant, shallow lake with a boathouse. It is in the boathouse that Marian finds Anne Catherick's dog dying. This sets a creepy impression of the place from the start. In this house, Sir Percival...