To save ammo and bypass the risk of a fight, Jill can instead choose to injure Plant 42 with a toxin called V-Jolt. To create V-Jolt, Jill must first solve a strange puzzle in the Spider Room of The Residence not far from Plant 42.
By taking the lighter into the Spider Room (located at the end of the hall just past the Residence save room), Jill can light red, green, and orange lamps scattered around the room. Each lamp reveals a different eyeball symbol when lit. Copy these symbols down. Then go to the pool table in the Spider Room and note the numbers on the Red, Green, and Orange balls on the table.
Later, when you reach room 003 just before the entrance to Plant 42's lair, you'll see a door with a keypad. On the pad, match each eyeball symbol from the orange, green, and red lamps to the corresponding number from the orange, red, and green pool balls you noted earlier. The door will open.
Grab all the jars inside and then, using the chemicals in the room, fill and combine them in the following order. Note that you'll need at least 4 empty inventory slots to perform this operation.
1. UMB no.3 + Water = NP-004. 2. NP-004 + Yellow 6 =UMB no.10. 3. Yellow 6 + Water = UMB no.7. 4. UMB no.7 + UMB no.10 = VP-017. 5. VP-017 + UMB no.3 = V-Jolt.
You'll now have V-Jolt in your inventory, a lethal plant killer. Now, backtrack all the way to the area where you first saw sharks, the flooded room where they chased you to the Aqua Ring lab. The area will be drained. Walking across the catwalk you'll find a room you haven't entered yet. Inside will be a part of Plant 42. Use the V-Jolt. Now, return to Room 003 and enter Plant 42's lair from the hidden bookcase door just beyond. A cut scene will play out and Plant 42 will be toast.
Chris
Chris is handicapped in this fight in two ways. First, he doesn't have access to the Grenade Launcher. Second, he doesn't have the ability to mix chemicals.
If you didn't save Richard from poison in the Mansion, this fight is easier. Before entering Plant 42's lair, unlock the Chemical Mixing room as normal. Chris is clueless about chemistry, but you'll still want easy access to this room later. Head into the fight with a shotgun and as many health items as you can find. Do not waste the Magnum here. You'll need it later in the game. As soon as Plant 42 grabs Chris, you'll gain control of Rebecca. Run back to the lab and make V-Jolt as described above. Run to the shark area and apply it the same way. You'll return to Chris.
