On the scariest night of the Dog Calendar, Doug locks the house and tells Dylan to keep everyone safe in the house, but Dolly manages to sneak out anyway. When Dylan realizes that Dorothy has followed her, he has to overcome his fear of the Boom Night in search of her.
The episode begins with Dylan screaming in front of a poster in the park advertising "Boom Night". He rushes about the park, trying to gather all the puppies together in order to get home before the fireworks begin. Dolly is skateboarding around the park and hanging out with the Canal Crew: Fergus, Sid, and Big Fee. Fergus offers that Dolly spend the night with them on the barge, but Dylan insists that she needs to go home and that the night is about "surviving". Fergus pulls his attention to Dorothy, who is trying to grab a stick from the bonfire pit. As Dylan tries to retrieve her, Fergus says that he'll see Dolly later, and she smiles in response.
Dylan attempts to pull the stick out of Dorothy's mouth leads to him falling back into the bonfire pile. He remarks that it is a "waste of perfectly good sticks" and is glomped by the pups, since "stick" is a trigger word. He is able to push all of the pups to the house. Doug greets them all and ushers them in to get earmuffs given out by Delilah. Doug starts breaking down at Delilah's feet over the night, and Delilah comforts him. She continues handing out earmuffs.
Dylan remarks there is less than five minutes until lockdown begins, and Dolly calls a group hug onto him much to her amusement. Delilah explains that Boom Night is the busiest night of the year for both her and Doug, but that she has full faith that Dolly and Dylan will keep the pups safe. Dylan reiterates to Dolly that no one in the household is going outside tonight, before realizing that Dorothy has taken his space helmet. Because of this, Dylan is given bunny earmuffs instead. Doug has a tearful goodbye with his pups as he goes off to work.
With the parents gone, Dylan tries to command all of the pups to listen to him. Dolly calls him "Commander Safetypants" and mocks his commanding tone. Dylan mocks her back about going to hang out on the barge. Dolly insists that no one needs to know about her leaving, but Dylan retorts that he will know that she has left and insists that their parents will find out. He orders her to stay put.
She is about to retort back, but Dorothy comes to her feet, so she plays like she's going to stay home. She asks if Dorothy can hear her, to which Dorothy shakes her head "no". Dolly sighs and decides to make some "anti-explosion gear", and Dorothy follows with a determined look on her face. Dolly's gear ends up being loads of tennis balls glued in a suit and a helmet, and she bounces down the stairs as she prepares to leave. She finds Dorothy has gotten stuck in her suit during her bouncing, and tells her there's no "too safe on a night like this". Dorothy giggles and is ushered upstairs so she doesn't see Dolly leaving. Dolly leaves once Dorothy is out of sight, but leaves the door open as she bounces away. Dorothy comes out from around the corner of the stairs and stares at the open door. Dolly bounces down the street and remarks on how protective her gear is, but slams into a trash can and slides down onto the sidewalk. She states that she's fine.
Dylan is preparing the pups with less than two minutes until the fireworks begin, but discovers that Dorothy is missing. He slips on Dolly's skateboard and discovers that the door is open as he falls down the stairs. He has a fight with his nervousness and decides that he must leave the house to find them. He gears up by wrapping himself in tin foil, wearing cans as boots and a colander for a helmet, then begins searching the streets. He runs into some firecrackers on the ground and is startled before he mistakes a garden gnome covered in garbage for a Martian, because the colander he is using for a helmet obstructs his view.
Meanwhile, Dolly has arrived at the barge, and tells herself to "just be cool" as she approaches. She trips and bounces off several objects before landing in front of Fergus, tennis balls going in every direction. Fergus remarks how "fetching" her attire is. Dolly mistakes Dylan falling down for the start of Boom Night and hides, saying that she should have stayed home. Fergus recognizes Dylan and states that Dolly is hiding on the barge. After the two make fun of the other's get up, Dylan tells Dolly to grab Dorothy and get home with him, to which Dolly responds that she doesn't have Dorothy and wasn't aware she had even left the house. The two argue about this before Fergus reminds them that Dorothy was enchanted by a stick in the bonfire pile.
The two go to the park to look for Dorothy, sneaking about on the way to avoid their dad from spotting them. Once at the park, the two become nervous with the commotion and large crowd. Dylan bumps into the bonfire pile and mistakes a white flag at the top for Dorothy. Dolly sees his mistake and tries to yell for him to get off. Dylan reaches the top, realizing his mistake, unaware that the humans are about to light the pile on fire, and the humans are unaware of him being on said pile. Dolly sticks her paws in some fountain spouts on the ground to propel herself up. As the pressure builds up, and Big Ben begins chiming, Dylan sees that Dorothy had been on their roof the entire time, and she is not wearing any ear protection. He tries to go down the pile, but is ushered back up by the building smoke. Dolly is propelled up by the fountain pressure and knocks Dylan off of the pile into a bundle of leaves. Dylan thanks Dolly, with Dolly apologizing, but she rushes Dylan onwards when he expresses surprise about her actually apologizing. As they leave, they spot Doug in his firetruck. He spots them at first, but as he rubs his eyes, they hide behind some trash and he shrugs. The two enter the house and run up the stairs to Dorothy.
Dolly's suit causes her to get stuck in the door to the roof, but calls out a trigger word, "ball", leading to an onslaught of pups strong enough to help her break free. Dylan covers Dorothy's ears just as the fireworks are launched, and she coos at the sight. Dylan opens his eyes slowly and is immediately in awe of the fireworks. The rest of the pups watch the fireworks as Dylan remarks that everyone is present and correct, and no pups' heads have exploded. Dolly remarks that "You've got to love this boom town". Dylan finishes with "Especially on this Boom Night".
- Josh Brener as Dylan
- Michaela Dietz as Dolly
- Bert Davis as Diesel
- Margot Powell as Dorothy
- Lauren Lindsey Donzis as Destiny & Déjà Vu
- Abigail Zoe Lewis as Dallas
- Rhashan Stone as Doug
- Ella Kenion as Delilah
- Connor Macniell as Fergus Fox
- Ben Bailey Smith as Sid the Squirrel
- Aimee-Ffion Edwards as Big Fee
- This episode is a parody of The Purge films.
- This episode is set during Guy Fawkes Night. While this is not said in the episode, the autumn setting and a poster that dates the episode on "Fifth of November" confirm it to be set during this occasion.
- During the search montage, Mister Fuzzy from "Dog's Best Friend" can be seen in silhouette with the park vendor, whom the Dalmatians hooked him up with in said episode.