Part Four: Summary of Chapter 1 - Chapter 170

The main points are:

- It describes events involving the characters Luo Feng, Nami, Anilu, Klockdar, Solon, and others who seem to be pirates or adventurers.

- Anilu is defeated by Klockdar. Nami gains powerful abilities after eating a thunder fruit.

- Luo Feng's group takes some islands using Nami's powers. They head towards an impending conflict at Marinford.

- Meanwhile, many other major pirate forces are also gathering, including the Whitebeard Pirates and other Emperor crews.

- Luffy breaks into the Impel Down prison to try to rescue his brother Ace, who is being transferred for execution. But Luffy is poisoned by the warden Magellan.

- As Ace is transferred away, Luffy wakes up and tries to escape with Ivankov's help. But they encounter Magellan again. The excerpt ends as a big clash seems imminent.

In summary, it describes various pirate forces converging and major events unfolding around Ace's impending execution at Marinford. A wide range of characters are involved in different storylines that seem to be building up to a climactic confrontation.