Wrong end of torpedo going off (3)
I believe the answer is:
sin
'wrong' is the definition.
(wrong can mean a sin or crime)
I cannot understand how the remainder of the clue works.
(Other definitions for sin that I've seen before include "Immoral action" , "Lapse against moral law" , "Moral offence" , "Breach of moral code" , "Serious offence" .)