From the outside... the building have multiple zip lines going down at different angles from different floors to the ground. Most tourist would just consider it 'building decoration'.
However the tourist sees something interesting, businessmen emerging from a hole next to the zipline. The tourist
then saw these guys hook a device nonchalantly to the line and suddenly zip down the line.
Just after the first business man zip down the line... the tourist suddenly saw another one from another zipline... and another from another one!
In fact its seems like multiple fleas were hopping off a building... rushing home to eat and sleep!
...
just another day at work i guess.