The Biolabs are located behind a powerful barrier in the Forest of Spirits. It contains La Croix' many undead experiments, such as Experimental Organism AD-5, Angel Ghoul and even a Zombie Dragon Girl . It also contains a device used to seal Alice.
The place is revealed by Chrome during part 3 if Luka dealt with her antics twice. The party end up accidentally splitting after Alice falls into an obvious trap, and forces Luka to fight on his own until he reaches La Croix. After dealing with her Cirque du Croix, she calls for Alice XV, but Luka's allies arrive, and Alice deals with her undead mother while Chrome deals with the Cirque while Luka take care of La Croix herself, removing the third member of the Seekers of Truth.