In Chapter 4 of The Chrysalids, what series of three consecutive crises temporarily distract David from his concern for Sophie?

In Chapter 4 of The Chrysalids by John Wyndham the crises that occur are a raid; a strange spider-like man; and a challenge about horses. (1) Some of the deviant mutants of Waknuk who have escaped to or been exiled to the outlying lands called the Fringe, raid David's part of Waknuk. Some of the leaders are captured along with a peculiar spider-like man who shocls David because he looks almost identical to David's fathre Joseph Strorm. (2) Causing another crises, this spider-like man eventually escapes and succeeds in making his way back to the Fringe.

(3) A third crisis occurs when Joseph Strorm's antagonist Uncle Angus Morton, a man with questionable principles on mutant-free purity and who is David's friend Rosalind's father, brags to Joseph Strorm that he just bought two horses that were of exceptional good build. Strorm suspects that Morton has gotten deviant mutation horses and calls in the government inspector, who vouches for the authenticty of the horses, which had been selectively bred by the government and were not the result of mutations.