Alex receives the fateful knock on the door in Sunday's Fair City on RTÉ One.
Sunday's episode sees Alex, played by Adam Karim, meeting his musician father for the very first time.
Teeing up the drama ahead, Fair City says: "Jon McCarthy, played by Paul McQuaid, walks into Alex's life under the guise of being the subject of Alex's college project. But Alex opens with asking is Jon married - an odd question to begin with for such an interview. Jon watches Alex as he nervously questions him on his life and music career.
"Jon opens up to Alex, saying that every year around his son's birthday he thinks of him and getting in touch, but he chickens out every time. But he ends by saying if he's anything like Alex, he'd be thrilled, acknowledging that they'd be around the same age."
Fans can find out what happens next on Sunday on RTÉ One at 8:30pm.
Fair City airs on RTÉ One on Sundays and Tuesdays to Thursdays.
