After a haunting encounter with a woman all in white, drawing master Walter Hartright finds a startling resemblance between her and his new pupil, the beautiful Laura Fairlie; Walter is then frequently consumed by the eerie sense of being watched.

Laura is forced by Mr Fairlie to set aside her love for Walter and marry Sir Percival, whose character takes a dark turn; meanwhile, Marian finds herself drawn to his enigmatic friend, Count Fosco.

Sir Percival goes to violent lengths to get his hands on Laura's fortune, while Marian starts to suspect there might be something sinister behind Count Fosco's charming facade; Marian is sure to find out what Fosco and Sir Percival are plotting.

Count Fosco and Sir Percival's plan is set into motion with tragic results; meanwhile, Marian and Walter make a horrifying discovery whilst seeking justice for Laura and a heartbroken Mrs Clements tells Erasmus that Fosco took Anne to London.

Following Mr Fairlie's betrayal, Walter, Marian and Laura are forced into hiding from Sir Percival and Fosco; with Fosco still at large and Laura's identity yet to be proven, Walter appeals to his Sicilian friend Pesca for help.