Before starting the chapter proper I went around delivering mail with Parakarry, it started with just three letters then the recipients would start to give me more letters and eventually I spent hours delivering mail. It was cool though the traveling between towns allowed me to train more. When I exhausted the letters I finally went East to the Forever Forest to rescue the third Star Spirit. At the entrance to the forest a Boo butler or Bootler meets the me and instructs me to travel to Boo Mansion and talk to Lady Bow. The forest teaming with Fuzzies and Piranha Plants was also puzzle like, if I went the wrong direction I ended up at the entrance, after braving the forest I finally found Boo Mansion and had to pass a couple tests set by the Lady of the mansion to get to the third floor. The third floor could be reached through a portrait but the portrait was gone from the frame. I had to get multiple items and use them in various fashions to get to the portrait, along the way getting the super boots increasing Mario's jump damage. Lady Bow introduces her self and her problem: Tubba Blubba is eating Boos and she wants Mario to find his weakness and defeat him. If Mario succeeds she will release the Star Spirit she caught as he was trying to flee Tubba Bubba. Mario agrees to her terms and Bow joins the team.
We then head to Gusty Gulch after making sure all the items in the forest have been found. At the bottom of the hill lies a locked wind mill, then abandoned huts which a group of Boos hang out. After speaking to the Boos and learning more about Tubba Bubba I witness a Boo get eaten by him. Then we continue up the hill to his castle. In the castle it was important to use Bow's ability to turn herself and Mario invisible to fool the guards and find the keys to get to the top floor. There I had to sneak past Tubba Bubba and get the key to Windy Mill where it is rumored TB's secret is hidden. But the key screams awakening TB and the race is on to get out of the castle, once out the Boos hold the door while I continue to run to Windy Mill unlock it and spin jump to get to the hidden area. Inside is TB's heart who explains how TB is invincible while separated from the heart. The heart is a worthy foe with 50 hp and very strong attacks but using Bow's ability to hide from the strong attacks I was able to get him down to almost nothing then he fled. Joining his body, I fought him again quickly defeating him. He then releases all the Boos he ate, and Bow released the Third Star Spirit. He gave me a new star power which attacks all enemies then returned to Star Haven.