No Mercy is the 15th book in the series. This is the story of Dev & Sam. According to the summary on Sherrilyn Kenyon's web site:
No Mercy – SummaryLive fast, fight hard and if you have to die then take as many of your enemies with you as you can. That is the Amazon credo and it was one Samia lived and died by. Now in contemporary New Orleans, the immortal Amazon warrior is about to learn that there’s a worse evil coming to slaughter mankind than she’s ever faced before.
Shapeshifter Dev Peltier has stood guard at the front of Sanctuary for almost two hundred years and in that time, he’s seen it all. Or so he thought. Now their enemies have discovered a new source of power- one that makes a mockery of anything faced to date.
The war is on and Dev and Sam are guarding ground zero. But in order to win, they will have to break the most cardinal of all rules and pray it doesn’t unravel the universe as we know it.
These are two wonderful and exciting characters. The depth of their losses and the pain they carry creates deepand painful lines in the fight to find something good in their lives. They need each other more than they realize and yet fight the attraction with everything they have in order to spare the other more pain. But love refuses to be held at bay and eventually nothing can stop the need and desire they have for each other. Not even the possible end of the world.
Here's a link to all of the Dark-Hunter books in reading order. Enjoy!!