W/in the Castle Walls

After receiving a strange voicemail from a solicitors. Nicki finds herself renovating a ruin in Devon, which once stood as a magnificent castle. A fresh start for her after losing her parents in a car crash and splitting with her boyfriend Jack. But Jack wants her now more than ever with her new found wealth and will stop at nothing to get it. Strange events begin to unfold, who is the strange figure who appears on the wallwalk, and can disappear in an instant, is someone else living within the castle walls?