When going for the Jackal after you are done with the mission with the blue square on it, you must go to a shack where he is hiding. When you get into the shack he gives you two choices. You can either take the diamonds or the car battery. If you take the diamonds, he tells you to take them and bribe the commander or take the car battery and fix the explosives. However if you take the diamonds, be careful with the large hole in the middle. If you drop in, you will not be able to get out.