Mystery of hound with no end, strangely (8)
I believe the answer is:
whodunit
'mystery' is the definition.
('whodunit' can be a synonym of 'mystery')
'hound with no end strangely' is the wordplay.
'no end' means to remove the last letter.
'strangely' is an anagram indicator.
'hound'+'with'='houndwith'
'houndwith' with its last letter taken away is 'houndwit'.
'houndwit' with letters rearranged gives 'WHODUNIT'.
'of' acts as a link.
(Other definitions for whodunit that I've seen before include "murder investigation" , "thriller" , "Crime story (colloq.)" , "American-style murder story" , "'A crime novel, colloquially (8)'" .)