涉世

涉 = 步 + 氵 : Sherlock Holmes (sh) suspects the five paced viper (步) to have killed an innocent person, so he is looking for it in the elevator's bathroom (e4). The snakes hides in one of the many water bottles (氵), so Sherlock has to wade (涉) through the bottles and the water in order to find the viper (步).

世 = 廿 + L : Mnemonic symbol: the WTO or WHO.

Sherlock Holmes (sh) is cleaning a flower pot (廿) under the shower of the space station's bathroom (Ø4) with a loofah (L) because he didn't quite understand a poster next to the shower from the WHO (世) explaining dangers arising from different germs.

In this case, L is for loofah.