After watching the cutscene that basically follows the end of the Casino Royale movie, you regain of Mr. James Bond. You start out in Mr. White's garden. Now, this is more of a training level than anything. M and Tanner will basically fill you in on most of the pertinent information on controls, etc.
Get past the camera
The first step is to eliminate or subdue the baddie standing guard. Note that if you eliminate him, make sure you use a silenced weapon or you will attract undue attention. Once he has been dealt with, run to the left side of the staircase and use it for cover as the second henchman comes to do his patrol. Wait until he is heading back to terminate him. Once he is gone, either take out the third goon from a distance or run up to the second set of stairs and take him out there. After that, you are going to go right, using the wall as cover. Tanner will come on, informing you of the security camera and the hacking station. Heed his advice, and stay down.
Once you are past the camera, if you did not destroy it, you can hack it instead. The hacking system goes like this: when you press you will get a small computer screen that contains one circle with what is basically your directional controls on your controller. Outside of the circle, at each point is a box with randomly moving letters and numbers. When one of the arrows turns green, press the corresponding or . If it turns red, do not mess with it, or you will lose time. The first hacking box is three digits, and you have 24 seconds to complete it.
Once you are done, go down the stairs and through the door to end this section and move on to the wine cellar beneath the Estate.
Run down the corridor and use either the wall or the pillar for cover. If you use the wall on the right, you are going to have to get to the other side, and you will be noticed. It's up to you. The important thing is to eliminate the two baddies in front of you. Once they are gone, head toward the pillar where two more will be waiting for you. Exterminate them, and move along the big wine rack toward the next pillar, where two more are waiting at the end of the corridor. Once they have been terminated, move down the corridor to the end. Once you are there, climb the ladder. Before you do, however, make sure you gather up all the ammo
You are now on the bottom floor of the Estate. Go through the only door to find a single guard standing sentry. It's pretty much a waste of ammo to eliminate him, unless you just want to do so, otherwise subdue him by sneaking up behind him, and pressing . Once he is out of the way, you can use the left wall for cover, so that you can get a feel for the place. There are two guards patrolling the upper floors. One on the second, one on the third. The briefcase is on the third floor, left side. Go through both doors, and to the safe. It's a hacking station, with three digits and nineteen seconds to get them in.
It's a trap! A number of enemies have entered the Estate. Basically, keep fighting them until Tanner tells you that Mr. White is trying to escape. Once he tells you, run for the front door to trigger a cutscene and a typical Bond opening.