### Clue: Shock in underworld after rising Mafia boss cleared out (9)
### Answer: BOMBSHELL 
 ### Explanation: Definition: Shock
 HELL(the underworld of the dead) **placed below**(after, in a down clue) [ **reversal of**(rising, in a down clue) MOB(the Mafia/the criminal organisation) + "boss" **minus its inner letters**(cleared out) ].