Cache is not at the posted coordinates. There is a puzzle to solve first.
The sixth in a series of puzzle caches with the common theme being that they are all situated "Inside No. 9". The Chiltern Society's Footpath Map No. 9 that is...what else could that mean?!
The Puzzle
Whilst the CO is a fan of the source material he appreciates that it is not everyone's cup of tea. There should therefore be no need to watch any episodes in order to solve the puzzles in this series, but it might help!
Congratulations to Balrogslayer's Mum on the FTF!