What do you do with a show about a child and his imaginary friend when your young star is very obviously growing up?
Answer: Go out with a bang on the big screen. Says Murphy: "There are rumours of a film - isn't it exciting? I can confirm that. We feel that we want to end it in a big way and we are not sure how we want to do that. The boys are growing up so it's a series with a short shelf-life. So you can't have an imaginary friend forever, so this story is going to end and we're figuring out how to end it."
What he's not saying here, of course, is whether they'll try and squeak a fourth season in and then do the film or if the film is up next to follow the third series but one thing is clear: It's all coming to an end soon.