Coronation Street's Eva Price will be left "completely shocked" when Johnny Connor starts custody proceedings of his late son Aidan Connor's daughter.
Catherine Tyldesley - who plays the barmaid - will have her life turned upside down when Toyah Battersby (Georgia Taylor) finally reveals that her baby Susie actually belongs to Eva and late factory boss Aidan (Shayne Ward), who took his own life before he found out he was a dad.
But Johnny is furious when he finds out his son was a father and announces he will fight for custody.
Catherine said: "She is completely shocked because when she first talks to Johnny he seems to react quite well and she thinks that everything is going to be OK and that they are going to be fair but she is unaware that he is hiding this overwhelming anger towards her.
"But she is a fighter and she is her mother's daughter; she can give as good as she gets which surprises Johnny."
A furious Johnny - played by Richard Hawley - will storm into the Rovers Return demanding answers from Eva after finding out the news that his son, who recently took his own life, was a father.
Johnny wastes no time in contacting a lawyer to apply for a Child Arrangement Order, but when his wife Jenny Connor (Sally Ann Matthews) disagrees with his plan, he gives her an ultimatum to support him or he will ditch her.
But Johnny faces a tough battle as Catherine insists Eva will "stop at nothing" to make sure she holds onto her daughter after already giving her away once.
Catherine - who has three-year-old son Alfie - added: "She is so ready, she has already given her up once she is not prepared to lose her little girl again. She is ready to play hard ball, much to everyone's shock.
"If it was me, nobody would ever take my little boy away, I would stop at nothing."