Ezio Auditore, the main character, needs to overpower and free Rome from the Borgia tyranny, that they are building up in order to become rulers of Italy
Very gruesome parts, for example on page 126 and page 127: "Overtaking a sixth, Ezio leant down and, turning backwards, ripped the man's stomach open so that his guts spilled onto the ground and he stumbled over them as he fell and died."
Many people die even in first pages of this book
Not recommended to people who can't stand tortures, especially when they describe them in detail

The author uses a variety of vocabulary; he uses a lot of different adjectives in order to not annoy the reader and make the story more interesting
There are many people that have really existed like Leonardo da Vinci, Michelangelo Buonarroti, Niccolò Machiavelli, the Borgia family and Caterina Sforza
The end of the book is the end of the book like many others; but it always leaves you a hint so that you can understand that it is not finished and that there will be a sequel (it did it also in the first book of the series). The last part of the book tells about these three great friends (I'll not mention the names if not I'll ruin you the book), that will divide to go in different directions but fate will join them again