To enter this room, Carlos has to activate the elevator first. The pack of Zombies can attack him when elevator arrives to the floor and doors are open. This random monsters can appear only once on any floor. If they had appeared on another floor, they won't be here. Also, two Hunters Beta will appear in this room, if Carlos enters from the Room 402 and he has just collected Vaccine Base and Vaccine Medium was already collected recently. If he goes first to the BF3, then to this area, an exploiding object will be attached to the wall. The Room 402 is closed initially by the key. It's necessary to have Sickroom Key in order to open it.