What is the ending of the masked hotel?

Keigo Higashino's "Masked Hotel" ended with the wedding as scheduled. The wonderful old lady who appeared once before reappeared and still asked for sister service. It turned out that she was the fourth murderer, deliberately trying to kill the hostess, the receptionist, the old lady who pretended to be blind. When she was young, she lost her child because of the obstruction of the hotel service staff, so she took revenge.

Extended data

Keigo Higashino's The Masked Hotel has a neat beginning, and the information about three murders is given through narration, which is quite compact and fascinating. The two protagonists of the story are the front desk sister and the undercover criminal police brother disguised as the front desk. The promotion of story line closely revolves around the particularity of the profession of "front desk", starting from their main customers every day, revealing the author's views bit by bit.

This is not a serial murder, so there are four murderers. The relationship between these four murderers is that the first three murderers were appointed by the fourth murderer. The fourth murderer was actually the old lady who pretended to be blind. The old lady pretended to be blind and checked into the hotel in advance. When I was young, I was stopped by a hotel waiter and aborted, resulting in the death of the fetus in my abdomen. The old lady who pretended to be blind had the idea of revenge for murder. First, she let the first three murderers leave clues to confuse the audience. Finally, she diverted the police's attention and thought thoughtfully.