When a TV drama has been drumming up spine-chilling suspense in the way that The Sister has, everything rests on the ending.

And episode four of the thriller, which played out on ITV this week, was both creepy and elusive, leaving viewers with as many questions as it did answers. 

For a recap (warning – spoilers ahead), The Sister follows the plight of Holly (played by Amrita Acharia) as she searches for answers following the mysterious disappearance of her sister Elise (Simone Ashley). 

Elise went missing three years before Holly met her future husband Nathan (Russell Tovey) and, unbeknownst to her, Nathan is hiding a dark and haunting secret. 

Along with Bob (Bertie Carvel), Nathan knows that Elise is dead, because he and Bob were there on the night she vanished: a fact that comes churning through to the surface in The Sister’s final episode.

In last night’s explosive finale, we see Bob admitting to Nathan that he deliberately poisoned Elise with drugs laced with cyanide, and admits that he has been haunted by her ever since.

Bob is desperate for both men to own up to what they’ve done, but Nathan – facing growing tension back home with Holly – plays for time. In a dramatic escalation of events, he eventually ends up trying to kill Bob by spiking his whiskey with sleeping pills. When the police arrive, they find Elise’s skull in Bob’s safe. 

Bob ends up in a coma. Although he opens his eyes at one point, shocking Nathan, it’s presumed he will stay that way, meaning that Nathan’s role in Elise’s death, and the fact that he slept with her in the past, remains conveniently hidden from the police. Holly, too, is in the dark; although it’s a close call as she discovers Nathan was there on the night Elise went missing.  

Holly and Nathan eventually reconcile and we fast-forward in time to see them struggling, but ultimately succeeding, in having a baby. All seems happy ever after – but as an elated Nathan drives away from the hospital after visiting his wife and baby daughter, the camera pans into the ghost of Elise, who looks directly at viewers from the backseat. 

Will the car crash, as Elise’s final act of revenge? Or is she simply a malevolent presence? We’ll never know, but the open ending split opinion amid viewers. Some on Twitter were delighted by the cliffhanger, and added in theories of their own:

However – as is often the case with ambivalent endings – other viewers were frustrated by the lack of answers, and criticised the “rushed” feel of the final scenes. 

The Sister’s lead, Amrita Acharia, has revealed that producers considered several different endings; but the one they eventually ran with got her seal of approval. 

“I found it really creepy [the ending] because I think there were a few different versions of it, I think there was a version with a crash. I loved it because it’s ambiguous, I think an ambitious end is a really great way to go,” she tells the Radio Times.

Referring to the final shot of Elise’s ghost, she adds: “It was really creepy, her eyes were so creepy. I was watching her going, ‘wow she looks really dead but not’. I liked it.”

All four episodes of The Sister are available to watch on the ITV hub now. 

Photos: ITV