After accidentally shrinking himself and falling down into the sewers, MK ends up in the Silken Web Cave. There, he tried to escape while running away from the Spider Queen. Although he was able to escape from her, he saw a little girl in trouble and was almost convinced by her to use the Golden Staff on the Trigram Furnace. However, once MK realized that the girl was actually Lady Bone Demon, the latter tormented him by lying to him that Monkey King picked the wrong successor until she was interrupted by the Spider Queen, allowing MK to escape.
After witnessing Lady Bone Demon's power, the Spider Demons began to get skeptical and decided rebuild the Arachnoid Base to defeat her. Although, once Lady Bone Demon realized that she no longer needs the Spider Queen, she tells the Mayor to get rid of her henchmen for her. Meanwhile, MK, who went to the Silken Web Cave to reclaim Pigsy's noodle sign after it was stolen from the Spider-Bots, destroyed the Arachnoid Base, thinking that the Spider Queen was rebuilding it to take over Megapolis.
However, once MK realized the truth about the Spider Queen and Lady Bone Demon's association, he tries to convenience the Spider Queen that they should work together. However, Lady Bone Demon arrives and the Spider Queen fights her long enough for MK to escape.
After escaping, MK went out to train outside Megapolis with his friends. Although, Lady Bone Demon and the Mayor used the Spider Queen as final ingredient, allowing them to create the bone mech. Once the mech was created, Lady Bone Demon used it to attack MK. When MK tried to destroy it by using his powers, it instead drained all of his powers and let Lady Bone Demon become more powerful and attain her true form, letting her become victorius. Before the Lady Bone Demon could finish off MK, however, Monkey King arrives and rescues MK from her.
After MK and the Monkey King met up with the others, Monkey King comes clean by saying that he was actually looking for a weapon that could defeat Lady Bone Demon. Upon hearing this, MK tells Monkey King that he and his team were coming with him. Due to the current condition he was in, Monkey King lets MK and the others join him in a quest to find the weapon and defeat Lady Bone Demon.