OK I got to the bottom of the facility and solved the Cryo lab puzzle I thought that would give me the antidote but it dd not, I also destroyed the attack of the killer tomatoes weed, clibmbed through the vent and got into the other room and killed both lickers but there was nothing of use there as the plant had destroyed everything. Is there a way to get the elevator to work and where and how do I get the antidote?