Marshall Hamston is the son of local councillor Colin Hamston and his late wife Rachel Hamston as well as the ex-boyfriend of Arthur Thomas. He currently resides with his maternal aunt Jean due to Colin's reaction to him coming out as gay.
Marshall meets up with Arthur and April Windsor at Café Main Street, where Arthur and April invite him to a party at April's home, which Marshall attends with his friends Gus and Tom. Marshall talks to Arthur outside, saying he'd like to go out on a date with him. Marshall and Arthur are about to kiss, when Gus and Tom appear from the upstairs window, saying Marshall won the bet, leaving Arthur humiliated and he runs away upset. The next day, Marshall tries to talk to Arthur, but April intervenes and punches Marshall in the face.
A few weeks later, Marshall tries to apologise to Arthur again. Arthur doesn't believe him, until Tom shows up and Marshall stands up for him when Tom taunts him. Laurel finds out that Marshall is hanging out with Arthur again and tells him to stay away from her son. Marshall finds Arthur after hearing his assembly about LGBT+ has been postponed and admits everything he said at the party was true and that he didn't know Gus and Tom were watching them. Marshall leans in to kiss Arthur, but runs off after receiving a call from his dad. The next day, Marshall meets Arthur, Laurel intervenes but Arthur gets her to back off. Marshall insists he isn't gay to Arthur and later witnesses Arthur's mum Laurel confront his dad when she works out he was responsible for postponing Arthur's assembly. A few days later, Marshall tells Arthur they can't be friends anymore and to leave him alone, he says being gay is sick and wrong, which he later retracts saying he meant he isn't keen on Arthur in that way but insists they still can't be friends.
Marshall decides last minute to turn up to Arthur's LGBT+ event at the village hall. Laurel avoids him from running into his dad Colin but later overhears Arthur when he goes to meet him outside. Arthur explains that he doesn't think he is being honest about his feelings but Colin interrupts them before it gets much further. Marshall once again meets Arthur to say that they won't ever be able to see each other again as his farther is sending him away to boarding school.
Laurel catches Arthur hiding Marshall in Rishi's house, she insists on him giving her his dad's number so he can tell her where he is. Colin meets up to talk with Laurel and Marshall where he explains he handled the whole situation badly, he convinces them he won't send Marshall to boarding school and that he can still see Arthur. At home, Marshall manages to message Arthur to tell him it was all a facade, causing Laurel to give Colin a visit. Colin calls to Marshall to prove to Laurel that he's fine and not locked in his room however after noticing bruises on his arm she confronts Colin who calls Marshall a liar and gets aggressive towards Laurel. Laurel offers to allow Marshall to come home with her which he wholeheartedly agrees. Colin insists that his son isn't gay until Marshall confesses that he thinks he is. Colin says his mother would be ashamed and then disowns him. Laurel says he can stay with them for as long as he likes.