Hmmm, it is a frightening fictional tale, yet many think it is the actual reality of the modern Church. Some think Malachi Martin was a prophet, some think he was a kook.
I thoroughly enjoyed it as a work of fiction. If you read it with that in mind, that's fine.
You'll have to then look at the signs of the times and decide whether, as some commentators say, it is 85 to 90% fact.