Slump to which there is a story (4)
I believe the answer is:
saga
'there is a story' is the definition.
(saga is a kind of story)
'slump to' is the wordplay.
'slump' becomes 'sag' (I've seen this before).
'to' becomes 'a' (I can't explain this - if you can you should give a lot more credence to this answer).
'sag'+'a'='SAGA'
'which' is the link.
Can you help me to learn more?
(Other definitions for saga that I've seen before include "Heroic narrative" , "Medieval Icelandic legend" , "A long adventurous story - it's a gas" , "Epic tale" , "Norse epic" .)