Final part of Madmen shown first? Fall to pieces! (7)
I believe the answer is:
shatter
'fall to pieces' is the definition.
(thesaurus)
'final part of madmen shown first?' is the wordplay.
I cannot really see how this works, but
'part' could be 'hat' (hat is a kind of part) and 'hat' is found in the answer.
'shown first?' could be 's' (1st letter of 'shown') and 's' is found in the answer.
The remaining letters 'ter' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for shatter that I've seen before include "Break into many bits" , "total" , "Crack" , "thoroughly upset" , "Break the minister into little pieces" .)