The Housemaid’s Secret

You pick up a few years after the events of the first book. The protagonist, Millie Calloway, has a criminal record (from book one) and is trying to build a life for herself: studying social work, working odd jobs, and in a relationship with a lawyer named Brock. 

She lands a new job with the wealthy couple: Douglas Garrick and his wife, Wendy Garrick. Douglas says Wendy is very ill and asks Millie to work in their Manhattan penthouse, with one firm condition — she must not enter Wendy’s locked guest‑bedroom.

As Millie settles in, she notices red flags: muffled cries, blood stains, Wendy’s condition doesn’t add up, and Douglas grows increasingly controlling. Millie’s past and her sense of justice pull her toward investigating what’s really happening behind closed doors.