Peter Barlow and Carla Connor have been compared to Richard Burton and Elizabeth Taylor.
The fiery on/off \'Coronation Street\' couple are set to see their relationship tested even further in the coming months, when a mysterious figure from Carla\'s past turns up to reveal details of her mental health crisis from last year.
Show boss Iain MacLeod told Digital Spy: "Peter (Chris Gascoyne) and Carla (Alison King) are the Burton and Taylor of the cobbles. I feel they\'re at their best when they\'re at their most explosive and they\'ve got big, heart-rending challenges to overcome.
"Certainly this will be a tricky time for Peter and Carla. What he discovers about her lost weekend will be a hard thing for him to swallow, but ultimately he will come to love her all the more for it and be all the more proud of her for overcoming it."
Although fans had speculated that Weatherfield newcomers Ray Crosby or Scott Emberton could be the key to unlocking what happened to Carla during her mental health crisis, Iain has explained that it will be a completely new character who helps to reveal all.
He said: "I can tell you for sure that it\'s not Ray or Scott - it\'s somebody we have yet to meet.
"It pertains to the time when she went missing during her mental health crisis. We wanted to revisit that at a point when Carla feels like she is back on an even keel psychologically, and now fill in the blanks.
"We don\'t know precisely what she got up to when she was away. We saw glimpses of it with the hotel and the squat, but we don\'t really know what happened.
"It felt like an interesting opportunity to delve into her recent story and generate something in the present, which will also reveal something we hadn\'t known previously about somebody else in the show."
