Because there is a complete randomness of where the enemies come from, I will not be mentioning any rough locations of where you will encounter most of the enemies - except for the ones you are most likely to find every time you play the level. Shooting some of the cameras in the level will decrease the amount of enemies you have to verse throughout the level - in particular, the second floor, so make good use of this tactic.

Once you start the level, immediately run up to the armed enemy standing ahead and knock him out first. Collect the Pistol, but knock out the second enemy straight away. Obtain the armour and remain crouched behind the table, so you are facing towards the doors. Wait several seconds until two more enemies, armed with Pistols run inside the office. Because you are crouched behind the table, they will not shoot you for some reason until they get close to you. This is the time were you make your move to knock out these enemies. Collect all ammunition after knocking them out.

Before you rescue Serena, you will need to open the Shutter Doors at the first floor that is blocking the way towards the area Serena is being kept in. The only way of opening these Shutters is doing it from the second floor, so do not move down the stairs for now. Take a right after leaving Diavolo's Office and pull out the Pistol. Use the Bond Sense to target the camera on the right wall and fire two shots to destroy it. Once that is done, turn right at the balcony overlooking the first floor below. As you head towards the archway leading to the balcony, use the Bond Sense again to target the camera mounted on the wooden pillar dead ahead. Destroy that camera and also the third one at the far left corner of the large room. Move towards the far right corner of the room until you see an enemy smash open the wooden door at the corner. Kill him and shoot the camera above the door before entering the room. Head towards the outside balcony, entering to it from the left so you can shoot the camera without it seeing you. From here, also shoot the Fusebox to open the Metal Shutters below. From here, backtrack all the way to the stairs leading to the first floor and kill the group of several enemies along the way. When you get to the first floor, hide behind the couch and first use the Strobe Grenade to disorientate the first wave of enemies. You can shoot them from here if you wish, but wait until the second wave runs in before using the Frag Grenade, hopefully killing most enemies. Move to the lobby area and kill the remaining enemies from here.

Once the area is clear, get to the outside area and open the liquor cabinet to end the level.