Whack the two bottles next to where you start, then head down the hallway until Bentley talks to you again. You'll see that the areas with blue carpets are guarded by dart-shooting world globes. You'll need to jump into the wooden barrel to get across safely. Once you're across, you can jump out and take out the globes in case you need to back through at some point. Take out the welder guarding the hallway, then jump back into your barrel and continue onto the lift the takes you down a level. Head across another blue dart carpet, and Bentley will tell you that you'll also be safe when in an enemy's flashlight, if you're stationary. Sneak up on the next guard, making sure to stop when he's facing you and jump out when you get close enough. When he's taken care of, look behind you and grab the extra life and the bottles in the mini-safe.
Continuing on you'll see flashlight enemy that isn't moving blocking the way. Climb up the ladder to the right of him and take out three bottles, then jump along the bookcase on the side of the wall back the way you came so you can get the bottle hanging from above. From up on the platform above the ladder, you can jump down on top of the enemy and get him before he has a chance to react. Go back and get in your barrel, because you'll need it upstairs. Over by the furnaces, get out and grab the bottles around each one, including the ones in the mini-safe, then sneak by in the barrel when they're not blowing fire. Walk across the blue carpet in the safety of your barrel, then grab the bottles on either side of the elevator before going up.
Follow the walkway over another dart carpet, then cross the bridge to the red security siren. Like the flashlight enemies, the spotlights won't trigger if you're in the barrel and perfectly still. After taking it out, grab the bottle there, then run up and break the books blocking your path forward when the enemy doesn't have his flashlight shining on them. Once you've created an opening, you can use the barrel to sneak up on the bad guy and take him out. Before getting back into the barrel, use the chandeliers on the side to jump up to the top where you'll find three clue bottles. Back down at the barrel, jump in and walk across the chandelier walkway to the other side of the room. Push against the bookcase on the left to reveal a secret area with a mini-safe holding two more bottles
Follow the path and you'll come to another bridge with two spotlights on it. Move across using the barrel for cover and grab the three bottles on the other side and break the red security siren. Now with all the bottles, except for maybe two, go all the way back to the other side of the upper area and you'll find the safe. Jump to the ladder on the side of the bookcase and use it to get to the top where the last two bottle are if you didn't get them before. After opening up the safe, return to where you left the barrel and use it to get across the blue dart carpet and grab the key there to finish the stage.