Halo

"The crew of the UNSC 'Infinity,' humanity's flagship, find themselves on security detail for a peace summit of Elites and Brutes--aliens with generations of enmity between them. When an unknown mercenary force ambushes the negotiations, Commander Sarah Palmer and her fellow Spartans must protect the diplomats, no matter what the cost. Along the way, they will unravel a plot of deceit, treachery, and revenge decades in the making.