One of the officers who knew reported, "Great King, the little fiends outside have already scattered."

They scattered in the previous chapter, when Wukong first told the pole-grinding story to the outer guard. The chiefs are only now finding out, which tells you how badly their own chain of command is working.

The old fiend said, "What do you mean, all scattered?

The first crack. He is no longer asking about the enemy, he is asking about his own people.

I suppose they got wind of it and thought it looked bad.

聞得 keeps 得 at the full dé — after a verb of perception it is the solid verb, not the light particle, and the sealed chapters have it that way eleven times. 風聲, wind-sound, is still ordinary Chinese for a rumour, so getting wind of something is the same metaphor in both languages.

Shut the doors, quick, shut the doors!"

Said twice, which is the book's way of writing panic. Everything the chiefs do from here is defensive, and every defensive move they make is one Wukong wanted them to make.

With a clatter and a bang the demons bolted and barred every door, front and back.

乒乓 pīng pāng is pure noise — two characters invented to sound like banging, and the same pair that later gave Chinese its name for table tennis.