The film also stars Camilla Rutherford, Patrick Godfrey, Olivia Llewellyn and Sean Hart.
"As for the children - they are all relative new comers (ranging from no experience to a bit of theatre and a short film). We did see about 75 kids, but these three had something very special and very natural. Of course, child actors can be difficult to cast, so we felt really lucky to find Sam, Hannah and George. They had to match their 'grown up' counterparts as well, which added a level of complexity. Their relationship as kids is pivotal to the film - if the audience didn't buy it, we would be sunk. They were fantastic though, so we are very happy."
The film's official synopsis:
Stephen is a brilliant young boy who lives in Cambridge, England, in what appears to be the 1920s – but nothing in Stephen’s life is quite as it seems. His world is turned upside down upon meeting a charismatic and inspirational professor at a garden party who demonstrates to Stephen and his friends what life would be like if they themselves were merely one, or two, dimensional beings. He then proceeds to explain that by manipulating other dimensions, time travel may actually be possible.