Question

Why was the man who had come to see Shonku outside the front of the door

Answer 1

Answer:

It looks like the Professor hasn't come back to Earth but his diary somehow has. The narrator then finds more diaries in Professor Shonku's house which detail his past adventures. These comprise the rest of the stories in the book

Explanation:

It looks like the Professor hasn't come back to Earth but his diary somehow has. The narrator then finds more diaries in Professor Shonku's house which detail his past adventures. These comprise the rest of the stories in the book