Fiz recently decided to join Tyrone (Alan Halsall) as he fled from the cobbles with his baby daughter Ruby, seeing this as his only chance of a happy future following Kirsty Soames's false allegations against him.
Tonight's (February 11) Coronation Street double bill sees the police catch up with Tyrone at a B&B in Wales. However, in a twist, Fiz is responsible for their sudden arrival as she has called them and confessed all.
Knowing that Tyrone is likely to be caught out either way, Fiz hopes that her decision will be for the best in the long run - giving the Weatherfield mechanic a chance to hand himself in before the situation spirals out of control.
McAlpine told itv.com: "Fiz has been desperately wanting to help Tyrone, but it leaves Fiz thinking, 'What are we going to do now?' She wants Tyrone to be okay with Ruby and for his plan to work, but she knows it's not going to.
"Kirsty's reported him and they're going to find them. So she wants them to be happy, but they can't be happy in that situation. She sees that her only alternative is to shop him to the police, but she does it because she loves him… She did it for the best."
After Tyrone is arrested again, life gets even worse for him as he is sent to prison to await his trial.
Tyrone forgives Fiz for reporting him, but he makes it clear that they should end their relationship as his chances of avoiding a jail sentence are slim.
McAlpine added: "Fiz is really distraught when Tyrone says he doesn't want anything to do with her. He says, 'Just leave me now, I'm getting you into so much trouble. Just live your life without me, you don't need me and my baggage'. But she loves him, she wants him with all his baggage!
"So I think it'll be Kirsty and Fiz round two. There's absolutely no way Fiz will stand by and let this happen. She isn't going down without a fight - no way."
Coronation Street continues tonight (February 11) at 7.30pm and 8.30pm on ITV.
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