WorstRivenNA

Can someone help me :c I'm stuck at Xen Lab where u need to find 4 keys to get to the main room but I can't seem to find the last one. I looked everywhere and I can't find it.

How is my team? Delphox Ability: Magician Nature: Modest Moveset: Psychic, Psyshock, Flamethrower, Sunny day Greninja A: Protean N: Hardy Moveset: Surf, X-Scissor, Feint attack, Extrasensory Leavanny A: Swarm N: Adamant Moveset: Leaf Blade, X-Scissor, Swords Dance, Slash Mawile A: Sheer Force N: Adamant Moveset: Crunch, Sucker Punch, Play Rough, Iron Head Ampharos A: Static N: Modest Moveset: Discharge, Signal Beam, Thunder Wave, Power Gem Sandslash A: Sand Rush N: Jolly Moveset: Earthquake, Swords Dance, Sandstorm, Rapid Spin 6 Badges atm Pokemon in box: Feraligatr, Pyroar, Toxicroak, Chesnaught, Xatu, Gothitelle, Hitmonchan, Vaniluxe, Exploud and my hm slave Bibarel