Brotherhood of the Rose
David Morrell
 It tells the story of Saul and Chris, two orphans who are adopted by a top espionage agent and trained to be assassins. When their adopted father tries to have them killed, their training, determination and loyalty are put to the test. The brothers find out that the conspiracy is even larger than they expected spanning security agencies of different nations, Each of the brotherhood member is 4th in ranking in the respective organizations and have loyal assassins trained from tender age. Chris died during a duel with one of the loyal assassins of another brotherhood member and the story became that of revenge. Their adopted father Elliot ran into a sort of national safe house for security agents which is where the later part of the book concentrated on. Saul being a Jew later went back to his native land and married his love interest Erica from their training days, who is a Mossad Agent. The other novels in this loose trilogy are The Fraternity of the Stone and The League of Night and Fog.