Many centuries ago Wu and Garmadon met a prince name Halbert. They were inseparable, but unfortunately Halbert had to return to his homeland called Knighton. However Wu and Garmadon kept in touch with Halbert by writing letters. Now with so many years gone by, Halbert decided to bring his daughter and her fellow knight friends to Ninjago and introduced them to his long time friend he hadn't seen in ages. Halbert wants his daughter and her knight friends to meet Wu's students and become friends with them. As for Wu, he doesn't know Halbert is coming to visit. Will things turn out right or go on the wrong path?