寂然不見 Silent, and Gone
那妖精與行者又鬥了十數回，見行者的棒勢緊密，料難取勝，虛丟一杵，將身幌一幌，金光萬道，徑奔正南上敗走。大聖隨後追襲。忽至一座大山，妖精按金光，鑽入山洞，寂然不見。又恐他遯身回國，暗害唐僧，他認了這山的規模，返雲頭徑轉國內。那妖精与行者又斗了十数回，见行者的棒势紧密，料难取胜，虚丢一杵，将身幌一幌，金光万道，径奔正南上败走。大圣随后追袭。忽至一座大山，妖精按金光，钻入山洞，寂然不见。又恐他遯身回国，暗害唐僧，他认了这山的规模，返云头径转国内。
逐句解 Line by line
The monster fought Pilgrim another dozen rounds, and seeing how close and heavy the strokes of his rod were coming and reckoning it would be hard to win, she made one feinting jab with her pestle, gave her body a shake, and in a myriad beams of golden light fled away defeated towards the due south.
She loses and the narrator says so plainly. What follows is not a rout but a manoeuvre: a feint, a shake, and a light-trail heading somewhere specific. 虛丟一杵 — a thrown blow that is not meant to land — is the same trick a fencer uses to make an opening. She is buying the half-second she needs to transform. Due south is a direction, not a flight. She is going home, and the narrator gives us the compass point, which is how we know Wukong will find the place.
The Great Sage went after her in close pursuit. Suddenly they came to a great mountain, where the fiend brought down her golden light, bored into a cave in the hillside, and fell silent and out of sight.
The chase ends at a hole in a hill, and the sentence ends on two characters that do a great deal of work. 寂然不見 — silent and not to be seen — is quieter than anything else in the chapter so far. Two hundred characters of clashing metal and shouting stop dead, and the reader is left looking at a hillside. 鑽 is to bore or drill in, the verb for going into a burrow. The book uses it three times in this chapter and every time the creature doing it is a hare, though nobody has said so yet.
And fearing she might slip away back to the kingdom and do the Tang monk some harm behind his back, he took note of the lie of this mountain and turned his cloud round to go straight back into the country.
He does not dig her out. He goes home, and the reason he gives is the correct one: an enemy who can travel as wind can be behind you the moment you commit to a search. 規模 is the shape and layout of a place — its scale and plan. Note the reading: 模 is mó here, the one appearance in this chapter that is not 模樣, where the same character is mú. He is memorising the terrain so he can come back to it. 遯身 means to slip the body away, to abscond. It is the more literary spelling of the ordinary word for escaping.
The fight ends and the chapter changes shape. Everything since the palace has been escalation — garden, sky, Heaven's gate, a thousand rods — and it stops on the quietest phrase in the chapter: silent, and gone.
What Wukong does next is the most professional thing he does all chapter. He has the enemy cornered in a hole, and he leaves. The reasoning is stated and it is sound: she travels as wind, his master is in a palace two provinces away with only a terrified king for company, and a burrow will still be there in an hour. Five hundred years ago this monkey could not be made to leave a fight.
He also does the thing that will matter later — he memorises the mountain. The storyteller gives that half a clause and moves on, and it is the reason the next two passages can happen at all.