The clause in parentheses, "that I found in my book," is a relative clause. It provides additional information about "the one" in the main clause and is introduced by the relative pronoun "that." Relative clauses often function to specify or clarify the noun they modify.
Adverb clause
adjective
adverb
adverb
adverb
adverbial clause
adverbial clause
The clause in parentheses is a noun clause, functioning as the direct object in the sentence. It introduces the idea of the surprise and provides more information about it.
adjective
adjective
adverb A+