Guest Stars Orla Bayne as Young Holly Mark Strepan as Rory Sawyer Emun Elliott as Alistair McDermid Sorcha Groundsell as Elizabeth Smith Evie Brassington as Young Georgia Chris Fulton as Charlie Lamont-Smith Daisy Littlefield as Lisa Grace Greatorex-Watson as Milly David Elliot as DS Tom Gillespie Siobhan Redmond as University Dean Clare Yuille as Invigilator