Xiaoming called grandpa for the first time when he was one year old, so grandpa died. It wasn't long before he called his mother for the first time and she died. Later, he called dad, Yu.

It is easy to understand that Xiao Ming in the story has a skill. As soon as he calls his relatives, they will die.

Then the relationship between the characters in the story can be straightened out:

Xiaoming's grandfather is the biological father of Wang Mujiang next door, and Wang Mujiang is Xiaoming's biological father.

In the story, Dr. Tsinghua thinks that the bug lies in "when Xiaoming called grandpa, it should be Wang Mujiang's biological father who died, not Xiaoming's grandfather".

The students of Jiaotong University made it clear that Wang Mujiang's biological father was actually Xiao Ming's grandfather (Wang Mujiang's mother knew who Wang Mujiang's biological father was), so she pointed out that "the carpenter's mother next door knew that this was not a BUG."