The couple try to flee Weatherfield with Tyrone's baby daughter Ruby in early February, fearing it is their only chance of a happy future following Kirsty Soames's twisted schemes.
Tyrone comes up with the idea after Kirsty falsely accuses him of domestic violence, and Fiz ultimately decides to go along with his plans.
McAlpine, who plays Fiz, told TV Times: "She's in love with Tyrone and knows he's the innocent party here. When he says he wants to take Ruby, Fiz tells him, 'I think that's a bad idea but I'll come with you'.
"It's because she can't live without him."
She continued: "Kirsty turns his closest neighbours against him. People he regarded as his friends start saying, 'We thought we knew him but obviously we didn't'. When Sally Webster takes Kirsty's side, it destroys him."
While viewers will have to wait and see how far Fiz and Tyrone get with their attempt to escape Weatherfield, McAlpine tipped the pair to stay strong and united.
She said: "These two are destined to be together. They're the perfect match, or at least they would be if they were both free. Then they would just get married. However, Kirsty is the spanner in the works. As long as she's around, things are never going to go well for them."
Coronation Street continues on Wednesday (January 23) at 7pm on ITV.
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