In Spite of All (Mourning Star, Vol. 1) 1st edition

It began with a dream of mushroom clouds, and it might end that way. Exiled and disavowed by the kingdom he swore to defend, Leon Victor could have faded into obscurity and lived the normal life he always wanted. Instead he carved out a place for himself among the mercenaries of Jackal Pack, operating in the gray areas between empires and laws.
With Leon's own disillusionment mounting after being left by Rachel Case, the woman he loved, he finds it more and more difficult to focus on his cruel work. Wondering if she'll return and tired of watching his colleagues die around him, his thoughts turn to retirement. But when he and his team agree to take "one last job" and find themselves at the center of a vast conspiracy, facing a mysterious enemy, they discover that there are some secrets the universe will not give up without a fight.
The first book in the Mourning Star series, In Spite of All assembles a diverse and compelling cast of characters to take readers on a journey to richly developed worlds, from the halls of galactic capitals to the arid frontier planet of Eve.