The Secret Room of Morgate House — Elissa Grandower

A young seamstress is lured to the home of her uncle and his family after her mother dies and finds herself among a family of strangers in a house with a sealed room, a staff of newly-hired servants, and a mysterious valet who searches the house at night. In time she discovers that her real uncle is, in fact, dead -- and in cold storage -- and that she is heir to a vast estate.