You must beat both the english and/or french quest line. There are two alternate endings, depending on the number of sub-quest line contracts you have completed. For example, if you complete more french contract, then by the time you get to the end of the main story questline, (these quest are marked with a (!)), then the the final contract will be French. Once you complete the main questline, this achievement will unlock, regardless of the explosives questline and engineering questline. ALSO, if you complete the game, it is safe to save. You can still complete the other two questline, and basically play quickplay contracts for as long as you want. Some contract difficulties will now appear with red stars, meaning basically insane mode. Those contracts shouldn't be much trouble, since most of your books are pretty ranked up. All in all the story with some side contracts, I did about 120 total contract, took me about 60 hrs. This game is not recommended for quick GP's!