隱血

隐 = 急 + 阝 : The pope (阝) and Maud Younger (y) both need to go to the bathroom in the encampment ((e)n3) urgently (急), but they both forgot the secret (隐) pass phrase so they cannot open the door.

血 = 丶 + 皿 : Mnemonic symbol: blood transfusion.

Xu Xian hurt himself and needs to get a blood transfusion in the elevator's bathroom. He found a petal leaf as donor, which is bleeding droplets into a bowl; Xu Xian gets the blood from the bowl as infusion using some tubes.