The spoilers for the Neighbours finale are below.
Guy Pearce, who grew up as Mike Young, agreed to reprise his role as Mike Young on one condition: that in the conclusion, his character would be Sam's biological father.
On the soap's Twitter page, the actress of LA Confidential and Iron Man 3 explained that Henrietta Graham is a "very kind friend" of his, and that he wanted to collaborate on screen before the curtain rolled over forever.
"I was very excited for her to join the cast a few months back at the start of the year. I couldn't believe it, I was overjoyed."
The GuyPearce's connection with Henrietta Graham is equally as pleasant in real life as it is on-screen! Guy discussed his desire to work with Henrietta and his wonderful suggestion for Mike to return to Ramsay Street as Sam's father!
"I've known their family before Henry was even born, and unfortunately and strangely, right on Henrietta's 18th birthday in February was the day I saw the show's conclusion," Pearce said.
"My first point of contact was to sort of check in and say, 'Well is she going to be able to film anything at all?' and then I found out that the program would continue shooting until the June, so she would at least get to do some work."
Mike and Sam's surprise connection might be a stretch for the Hollywood star's immediate goal, otherwise his return might appear strange.
"It's a real pleasure to get to relive my childhood and play Henrietta, and particularly her father," he said. "The producer and the other writers I think were very happy with that idea immediately."
Herbison explained this further in an exclusive interview with Digital Spy: "Guy was fantastic. We had a structure for the story, which included revisiting Mike and 'plain' Jane. But he brought so much more to it. It was his idea that Mike turn out to be Sam's father, which we all thought was one of the most heartbreaking parts of the finale."
Neighbours has come to an end, but catch-up episodes are available via My 5 (UK) and 10 Play (Australia).
More Neighbours coverage may be found on our dedicated homepage.