As ITV thriller Cheat continued last night, viewers bombarded social media with theories over a potential secret connection between protagonist Leah and her nemesis Rose.
The four-part story follows university lecturer Leah, played by Corrie's Katherine Kelly, who accused one of her students (Molly Windsor) of cheating on an assignment.
Rose took the accusation badly and with Leah's life now falling apart, she's fighting to uncover the truth about what's happening to her.
The shocking series opener, aired on Monday, saw the lecturer's cat Betsy murdered and viewers were absolutely mortified.
During the second instalment, Leah's husband Adam (Tom Goodman-Hill) was seduced by Rose, who obtained a sexually explicit photo of him and sent it to his wife in the closing scenes.
Viewers had no sympathy for Adam whatsoever and took to Twitter to drag him over the coals, even though we know from a flash-forward that he dies at some point in the series.
My theory on #Cheat... Rose is her daughter. Put her up for adoption yrs ago, hence the reluctance to have a kid now.
Now, viewers on Twitter think they've managed to crack exactly what it is that's driving Rose's vengeful ways - and, perhaps not surprisingly, it's not all about the cheating accusation.
One user offered up the possibility that Rose is Leah's daughter, tweeting: "My theory on #Cheat... Rose is her daughter. Put her up for adoption yrs ago, hence the reluctance to have a kid now and Rose stalking her."
That stance was echoed by many others, with some suggesting that Rose could even turn out to be Leah's sister or half-sister.
Another reasoned that it would make sense for Rose to want to ruin Leah's "perfect life and marriage" if the latter abandoned her when she was little.
Cheat got off to a particularly raunchy start before firmly establishing itself as one of ITV's darkest thrillers of recent times.
Within the first five minutes of the first episode, viewers were shocked to see Katherine Kelly's character performing a solo sex act in a toilet cubicle while fantasising about a colleague she fancies.
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