Incinerator

Incinerator is the pulse-pounding sequel to Crusher, Niall Leonard's debut YA novel and an Edgar Award finalist for Best Young Adult Novel.
Following the bloody deaths of his mother and father, Finn Maguire is determined to make a fresh start, running a boxing gym in the bruised and bitter heart of the city. But when loan sharks target his business partner and his lawyer vanishes with all his money, Finn is dragged down into London's underworld once more, with only his fists and his wits to keep him alive.