The Sister continues on ITV on Tuesday night and there's one character that has got everyone talking.
After true crime drama Des and Honour proved big ratings hits for the channel, The Sister made its long awaited debut on Monday night, with millions of viewers immediately gripped by the massively sinister thriller.
The Sister cast is led by Russell Tovey as Nathan but is is Bob, a shady character from Nathan's past that sent the biggest chill down the spines of people watching at home.
The plot centres on a dark night from Nathan's past which saw the death of young woman Elise and the fact that Nathan is now married to her sibling Holly.
He receives the shock of his life when Bob turns up at his door years later with some life shattering news and the end of the first episode saw Nathan start believing that Elise was actually still alive, not helped by some very strange and unnerving behaviour from Bob which didn't go unnoticed by viewers.
Bob is played by Bertie Carvel, looking remarkably different from the role he is most famous for - cheating husband Simon in Doctor Foster.
One tweeted: "Lovely watching The Sister with @bertiecarvel as creepy Bob love it!!!" and another reacted: "Not being funny but if my husband had some random ‘Bob’ in our hallway while acting all cagey then I’d wanna know who the hell he was!"
The Sister has four episodes with them concluding on Thursday night.
