A definite article is used because "events" is referring to a specific set of things that happened. Without further context, I couldn't say what those things are. Presumably the book details a specific set of happenings, and "it" is becoming involved in those specific happenings.
Consider this sentence from the introduction of the book The Airship ROMA Disaster in Hampton Roads (by Nancy E. Sheppard), a book detailing the crash of the airship Roma:
The events you're about to read have been collected through extensive
research from personal letters, essays, articles, official testimony,
interviews, imagery, genealogy and notations from archives and libraries.
In this case, the sentence refers specifically to what happened regarding the crash of the airship.