Carey Mulligan, Joanna Lumley, Mackenzie Crook & Christopher Eccleston have been cast in Simon Aboud's This Beautiful Fantastic:

This Beautiful Fantastic recently appeared on The Brit List, an annual compilation of the best unproduced screenplays in the UK which is generally regarded as an indicator of future critical favourites...

A modern fairy tale in the vein of
Amelie and Finding Neverland...The film will focus on frustrated children’s author Bella Brown, who only leaves her obsessively ordered flat for work at the library. Chronically shy, she has no friends, no family and no life until she falls in with Billy, a hopelessly messy inventor who whirls through the library’s carefully balanced world like a shambolic tornado.
Beautiful Fantastic source