Bingo sneaks behind a chair in the sunroom, trying to enjoy a pilfered biscuit without getting caught. However, Chilli has been watching from the window and calls out her mischievous behavior, labeling her “a bit of a cheeky kid today.” Feeling judged, Bingo storms off to her room to sulk. While under the bed, she discovers a horned helmet, which instantly lifts her spirits. She decides to put it to use and enlists Bandit’s help to play Bad Mood.
With the helmet on, Bandit has Bingo stand on his feet, using her as a puppet to knock things over. Bad Mood Bingo leaves a trail of chaos through the playroom and even gets into Chilli’s washing, finding the whole ordeal hilarious. Bluey recognizes that her sister needs cheering up and takes matters into her own hands. She starts by confiscating the remote control when Bad Mood Bingo tries to watch cricket, and then takes away a chocolate bar from the fridge. Bluey suggests that Bingo try relaxing in her special chair and practice some deep breaths, but Bandit’s fidgeting disrupts the attempt, and he eventually storms out.
The attempts to calm Bad Mood Bingo continue, with Bluey suggesting drawing as a way to express her feelings. She draws a unicorn, but Bad Mood Bingo adds an angry face and a pile of poop to the picture. They then crumple up the drawing and storm out again. Later, Bad Mood Bingo is found unrolling all the toilet paper in the bathroom when Bluey surprises her with a boombox playing the lollipop song. Despite Bluey’s efforts to get her to dance, Bingo remains in a bad mood. Bluey tries to turn the situation into a game of hide and seek, but it doesn’t work. She eventually retreats to ask Chilli for advice, and Chilli suggests that maybe Bingo enjoys being in a bad mood. Bluey comes up with a new plan, creating a clay house as bait. When Bad Mood Bingo tries to squash it, Bluey takes off with the house in the pedal car. After a wild chase, Bluey finally manages to grab Bingo and hands her over to Chilli, who is wearing a sun hat. This marks the transformation into Good Mood Bingo, who proceeds to hug trees, gnomes, and pedal cars. In a surprising turn, Bingo decides to give the Bad Mood a hug, saying “he’s not bad, he’s just behaving bad.” As she does, the helmet falls off, and the Bad Mood smiles.