Skeletons in the Closet

The closing events of The Fire Rises gives way to an old nemesis from Deeks past. He has come back to put an end to the ten year dance they have been doing. Will Deeks be able to finish what he has started ten years ago, or will he be the next victim? It would also seem that another skeleton is going to come out, but this one is far older. How far back does it go?