Coronation Street fans are gripped by the ongoing storyline with newcomer Lydia Chambers, who is targeting her ex Adam Barlow.
After recent scenes teased she was out to get him, Lydia has also been targeting his wife Sarah Platt.
Actresses Rebecca Ryan and Tina O'Brien take centre stage in the dark new plot on the ITV soap, with more to come.
But some fans had completely forgotten this wasn't the first time the stars who play the characters have filmed closely together.
In fact, Rebecca and Tina were in the cast of BBC series Waterloo Road around the same time in 2010, remaining on the show until 2011.
Rebecca actually joined in series five as Vicki MacDonald, while Tina's character Bex Fisher joined in series six.
The pair filmed a lot of scenes together, with Vicki being the best friend of Bex's sister Jess.
Now, 12 years on, the actresses are back filming closely together again - something Rebecca noted she was excited about in a recent interview.
Viewers were quick to notice the Waterloo Rod reunion at the time, recalling the pair's past show together a decade earlier.
But some fans have only just made the link, and recently took to Twitter to share their surprise at the pair's past roles.
One viewer tweeted amid the storyline: "Oh my god I completely forgot she and Tina worked together."
Another shared a snap of them on Waterloo Road, with the caption: "Long before Lydia was trying to ruin Adam in #Corrie #WaterlooRoad."
A third asked: "Didn’t Tina and Rebecca costar in Waterloo Road together?"
Meanwhile another fan commented: "It’s mad seeing Sarah and Lydia act together again from way back on Waterloo Road."
A fifth fan wrote: "Sarah and Lydia just reminds me when they were in Waterloo road as bex and Vicky," while another said: "Love a waterloo road reunion me."
Coronation Street airs Mondays, Wednesdays and Fridays at 7:30pm and 8:30pm on ITV.
