I have completed the grid and have loads of extra letters to make the 3 word phrase but apart from one 11 letter word that I think is relevant am really stuck! Can anyone help please?
Are some of the six 4 letter words top right and bottom left ones that are 'seriously' altered?
Sorry I'm struggling, obviously the centre one (25a) must be one.
A further tip for smallest interval at 1a would help too.