Lots of people have the idea that a prepositional phrase at the beginning of a sentence needs a comma depending on how many words it has in it.
(First, let's be clear that we are talking here about prepositional phrases that just modify. We are NOT talking about "in my opinion" or "by the way" and phrases like those because those are parentheticals and the rules are different.)
The comma after a prepositional phrase isn't really about "counting" words. For example, "in a big house" is four words; "beyond those incredible circumstances" is also four words. It isn't about the number of words, per se.
Further, that "count-the-words rule" is not a rule but a suggestion. I am going to say that USUALLY four-word prepositional phrases do NOT take commas and that five-word prep phrases do. One of the things that has to be taken into consideration is the "length" of the words.
So we wouldn't put a comma after "in a big house," and we probably would put a comma after "beyond those incredible circumstances" even though each one is four words.
The comma is about pointing out to the reader that the main part of the sentence is coming because he might not catch that the phrase is over and the sentence is starting.
It is not about simply counting words.
Happy punctuating!
Margie