Day of Reckoning (en Inglés) - Rebecca Deel

After Fortress Security operative Elias Knight is shot in an assassination attempt, Iona Byrne, driven by loyalty and perhaps something deeper, doesn't hesitate to join his security detail. Before his wounds can heal, he is tapped for an undercover assignment requiring his unique background. Even with their black ops teams rallying around them, the odds are still stacked against them. Elias soon realizes that Iona and their friends are now targets for a killer. When Iona and Elias fall into the killer's trap, they learn the worst betrayal of all is at the hands of those closest to you. One misstep and they'll pay with their lives.