Infinitum: Subject Unknown
- taona: 2021
- Firenena: United Kingdom
- Genre: Science Fiction, Thriller, Mystery
- Studio: Fizz and Ginger Films, High Octane Pictures
- Keyword: london, england, experiment, escape, alone, quantum mechanics, confusion, futuristic, memory loss, time loop, fear, tied up, attic, research facility, hopelessness, groundhog day, stuck, scientific experiment, repeating day, possibilities, experimental research, science experiment
- tale: Matthew Butler-Hart
- Cast: Tori Butler-Hart, Ian McKellen, Conleth Hill, Wendy Muir Hart, Christopher Hart, Matthew Butler-Hart