These are the tenth, eleventh, and twelfth missions of the game.
On Montenegro Train, make sure you use a lot of cover. You start in one train car and you have to move up the train through other train cars.
On Casino Royale, you have to be extremely stealthy during the beginning of the mission. Refer to “Any thug can kill” for tips on how to get past the beginning of the level. Once you reach the spa area, make sure you use a lot of cover because enemies will come from all around you.
On Casino Poison, you are poisoned and have to get out of the building into your car. Always keep moving and when you reach a new area, remember where to go when the screen shows you. There are no enemies on this level so you don’t have to worry about cover.