Like in the first Godfather movie, the part which puzzles most moviegoers in the second one - Is the mysterious mob hit on Michael Corleone& his family, and the events following it.
It all begins from the first quarter of the movie, the moment we see Michael having a business talk with Frank Pantangali, where the latter advocates the proposed assination of one of his business rival's - Hyman Roth's- henchmen "The Rosato Brothers" and the former opposes it.
For Pantangali, Ros brother's are a nuisance& a hindrance(to his business growth) hence he wants them dead as soon as possible. For Michael, they are a nuisance but not a hindrance - via Hyman Roth - that is why he opposes Frank.
After the exchange we see a Mob Hit on Michael Corleone& his wife which sparkes off that fabulous question - who hit mike, why& how mike comes to know about it..?
Before I answer that tricky question lets analyze some facts.
These mobsters are extremely intelligent people. Whatever they do, especially killing, is characterized by selfish motives.
From the Tom Hagen-Michael Corleone exchange we come know about the advice which Vito gave to Mike - " Try to think like how people around you would do."
He also says to Tom that right now, he's the only whom he trusts - completely.
During the Pantangali - Mike exchange, Mike explains about his father's gratitude towards Pantangali - eminently quoting out " You were a loyal servant to my father, He trusted you so much".
The best way to find out an answer to that question is to put ourselves in Michael's shoes& try and think like Michael Corleone would do in that situation.
For this, let me give you a sneak peak into Michael Corleone, the individual. Michael adhers to most of his father's principles. From the movie, its quite clear that Mike follows his father's advices& most of his thought process resembles very closely to that of his father.
Because of this Mike also trusts Pantangali to quite a degree, like his father used to, within his prejudiced mind.
He also presumes that if Pantangali wanted to kill ths rosato brothers, he would have done it himself.
Frankie's approach to meet michael& seek his advice, itself has pleased the latter, despite he turned down down the offer.
When somebody Hits him& his wife he straightaway presumes that it is Hyman Roth. WHY..? Because Pantangali had already warned him out'Do not trust Hyman Roth'. Because he trusted Pantangali like his father did.
Lets face it - He knew it was Roth all the while. He knew about Roth's intentions. He also knew about the Roth-Moe Green connection which is later revealed by Roth himself.
Freido previously took sides against the family with Moe q which means he suspected his brother's involvement as well.
Despite having Tom Hagen& so many others, Mike intentionally gives the money carrier's Job to Freido - so that he could somehow or the other confirm his brother's involvement in the same.
When Freido comes, Mike intentionally mentions Hyman Roth& Johnny Ola to find out how his brother would react. Friedo says no but to his bad luck he clarifies all of Michael's doubts by spelling out both Ola as well as Roth's connections with him during the nightout, inturn leading to the killing of Johny Ola, Hyman Roth as well as his own brother Freido.
What is so special about thess characters, the exchanges& The Godfather movie's in general is that the writing is so intricate.
Coppola& Mario Puzo wrote these characters by colouring them with "Grey" and he leaves it to the audiences to find out all these how, why& where questions through social discussions instead of spelling out in the screenplay.
Michael is wonderfully well played by Al Pacino and it was his ace performance which gave birth to one of the most mysterious& aching screen character in all of movies.
Is he a Villain or is he a Tragic Hero..? Well, I don't know but I know this much.
That, its because of his righteous, calculated decisions the family business goes upwards.
At the end of the day - " Everything is Business and nothing is Personal."
Thank you very much for reading.