Saw 1, the entire plot, I don't understand what it means. Don't copy the people who have seen it in the encyclopedia and say it

Saw was a classic horror novel written by William Yubin. The story was about a group of criminals called the Chainsaw Gang. They used a violent method called the Chainsaw to rob banks and kill people. The protagonist of the novel was a policeman named Adam, who was forced to join the chainsaw gang and step by step into danger. The turning point of the whole plot was the duel between Adam and the chainsaw gang member "Saw"(a black man). In this duel, Adam was forced to fight to the death with the chainsaw gang members in order to protect his friends and his profession as a police officer. In the end, Adam successfully defeated the "saw" but also became a member of the chainsaw gang. In the novel, Adam experienced a series of terrifying events and dangerous trials, including having his fingers cut off by a chainsaw, being imprisoned in a dark basement, being kidnapped, and so on. He kept trying to escape but failed every time. Finally, he realized that he could only protect himself and his family against the chainsaw gang, so he began an arduous escape journey. The novel, Saw, was known for its thrilling, terrifying plot and deep character descriptions. It was loved by readers and audiences.