The entire first floor of the Lighthouse belongs to the "Nurse Station".
When Han Dong steps down the stairs, he immediately understands why Mr. Aha asked them to enter from the side door on the sixth floor.
Not to mention, entering directly from the main entrance to the first floor would attract the immediate attention of the "Head Nurse", and they would be attacked by tens of thousands of nurses all at once.
The 'ground' of this floor is extremely unfriendly to outsiders.
No cement has been used to fill in the gaps, no floor tiles have been laid... instead the floor is entirely composed of piled syringes, and stepping on it would inevitably result in syringes sticking into one's foot.
As for the "Head Nurse", she is also troublesome.
Centipede-shaped.
Each of its segments consists of a slim nurse, and the 'feet' used for mobility are flexible scalpels, allowing the Head Nurse to crawl freely on the syringe-covered ground.