After finally managing to get along with his father in law, Shrek is making things work for him and Fiona. At one point, king gets ill and passes away. That makes Shrek the next one in line to the throne. But, that is something he wasn't expecting to and doesn't know what to do. Being jealous, Prince Charming renounces that he is, in fact, the real successor to the throne. This makes Shrek even more determined to find the real successor, so he goes on the adventure. Finally he manages to find Arthur, a young boy who is still in school and isn't prepared for what is about to come. While Shrek is trying to convince young Arthur to come and take the throne, in the Land Far Away lots of things are going on. From the siege of the whole city by the Prince Charming and his army that consist of Witch, Captain Hook, Rumplestiltskin, and lots of fairy tale villains, up to Princess Fiona giving birth to their first child and trying to keep the girls safe, you can say without any doubt that there is a complete chaos in the land. Will Shrek make it in time and convince Arthur to become king and take over the throne before Prince Charming does the same?