Guest Stars Oscar Kennedy as Young Liam Sam Bottomley as Ralph Roberts Aqib Khan as Adnan "Addy" Masood Shaun Thomas as Tom "Craggy" Cragg Rosie Cavaliero as Linda (Liam's Mum) Steve Pemberton as The Gardener Don Gallagher as School Interviewer Emma Beattie as Cambridge Interviewer Jemma Churchill as Mrs Peacock Andrew Turner as Fake Librarian Joel Phillimore as Marcus Gareth Kane as Solar Panels Customer Olivia Jerdin as Kara