Callum has allowed George (Steven Roberts) to stay with him over the past few weeks after life on the streets became very dangerous for the homeless teenager.
However, George starts to question his place with the Kane family this week as they prepare to move house - and things become more complicated when Callum's younger sister Lacey (Georgia Burke) makes an unexpected return…
Laurie Duncan, who plays Callum, recently chatted to Digital Spy about the ongoing homelessness plot and more.
After a few months on screen in Hollyoaks, how are you finding your time on the show?
"It's been absolutely fantastic so far. We have the best fun here, and I've met some of the best friends that I've ever made. It's a brilliant place to work."
Callum has always been a character with a slight air of mystery around him. How do you describe him to people?
"I think, most of the time, Callum is the kind of character who just doesn't really want to be bothered by anything or anyone. He wants to do his own thing, get on with his own life, and he's very introverted.
"At the same time, we've also delved a bit deeper with him recently - and that's been very nice, actually. The storyline with George has been great, because it's shown that he's not just an empty shell. I think the viewers are seeing a more human side to him now."
"I think Callum just thinks that George is a really nice person. Callum is very caring deep down, and he can obviously see that George is in a lot of trouble. Because of that, he really wants to help out and make sure that George is okay.
"In real life, I also get on really well with Steven Roberts, who plays George. We're best friends, and we're pretty inseparable at the moment as we work together so much! On the rare days when I'm not working with him, it feels strange. We have a lot of banter and jokes going on between us."
You and Steven recently visited a Centrepoint service in Soho to learn more about youth homelessness. Was that useful?
"Definitely. We went down there to see what kind of facilities they have, and what kind of support they give to young people who are homeless. It was a real insight. We met one guy called Tom who'd been on the street for almost a year, but then he found out about Centrepoint - and his life has changed a lot since he's been there. It's quite incredible how they're helping to change young people's lives around."
Is it nice to be part of a storyline that's quite topical and hard-hitting?
"Yeah, definitely. I don't think there's much else in the film or TV industry that is tackling this issue at the moment. It's nice, because I don't think people are really aware of homelessness among young people. It's happening all over the country, so it is nice to be able to raise awareness of it."
In this week's episodes, we see the Kanes preparing to move house. What does that mean for George?
"Callum is really keen for George to keep staying with him, but with the family moving, George doesn't want to intrude. Callum keeps trying to talk him round, though, as he's really quite eager to get George away from the streets and into a stable structure again."
"Lacey is very fiery and a bit mouthy! But she's a great character and Georgia, who plays her, is fantastic. Callum has a bit of a love-hate relationship with Lacey, and as her older brother, he's always thinking that he knows best.
"Callum is almost trying to be a bit of a father figure with Lacey. I think Lacey can probably see that he means well, but his attitude annoys her a little bit as well! And for George, it's another member of the family that he has to win over."
Have Callum and Ash always got on well?
"Yes - Callum loves his sister very, very much. He doesn't like to admit it, but Ash is his best friend and she's helped him through a lot over the years."
Are you glad that the Hollyoaks producers are expanding the Kanes?
"I'm really enjoying it, as I think we're getting a big insight into everything that Callum has been through before. It helps us to explore why he is the way he is, and I think it'll hopefully explain a bit more. With the sixth formers, Callum is a bit of a black sheep, so it should be interesting to see if he's like that within his own family as well."
"I think he's slowly getting in there, but I think he's still not all that fussed, to be honest! He's doing it to please Maddie more than anything else."
Do you think Callum and Maddie are a good match?
"I think they have very different personalities, but they're so different that they're good for each other. Maddie brings out quite a fun side to Callum. At the same time, Callum is trying to get Maddie away from the image that she's been hiding behind. He'd like to make her a bit less bitchy!"
Would Callum be annoyed if he saw some of Maddie's nastier moments?
"I think he would, yeah. If Callum saw Maddie being horrible or rude to people, he wouldn't be very happy - and he'd definitely let her know about it."
How did you get into acting?
"Acting is something that I've always wanted to do, for as long as I can remember. I remember being at primary school and doing a play, and that was probably the first time when I thought it could be for me. I attended a few stage schools on Saturdays for a while, but then I got out of the loop for a little bit.
"In late 2010, I was unemployed and I couldn't find a job. That was the point when I decided that I'd get myself a proper agent, concentrate on acting and do it properly. I did Law and Order and then a few months later, I got on to Hollyoaks - and it's been great."
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Hollyoaks airs weeknights at 6.30pm on Channel 4 with a first look screening at 7pm on E4. Get the Inside Soap magazine on your iPhone or iPad