For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Pericles runs for his life from another king who wants to mount his head on a wall.
Act II
Pericles gets hitched and has a baby... and then promptly loses his entire family.
Act III
After a long, wandering journey full of heartache, suffering, and a gazillion tempests, Pericles is reunited with his wife and child. Hooray.