T. J. Andrews & Simon Scarrow 
Arena: Revenge (Part Four of the Roman Arena Series) [EPUB ebook] 

The opening day of the Games in Rome is a time for celebration in honour of the new Emperor. But for Marcus Valerius Pavo, a young military tribune fallen from grace, only despair awaits. Along with former mentor, Optio Macro, Pavo must fight for his life in a ferocious beast hunt. Battling against lions and bears, he’ll have to use all his wits to survive, as well as the help of a hated former rival. But when Pavo achieves a stunning victory, his reward is to be condemned to death in a chaotic free-for-all. Now the young gladiator faces a race against time to triumph over the odds, save his son — and exact the ultimate revenge over the Emperor…