Parker, Jack, Douglas, and Spencer head to Happy World to hunt Ghosts. Unfortunately, while Douglas was distracted playing with the High Striker, Parker and Jack were captured by Tragico in the House of Mirrors. The two are tied on a roller coaster and as they are riding to certain death, Douglas comes in to save them. He splits the carts in half and ends up crashing. When Parker and Jack check to see if he's okay, he is thrilled with the experience and wants to do it again. Tragico allows him to ride another roller coaster as Parker and Jack lay off on capturing Tragico.
Parker, Jack, and Douglas are flying in Douglas' Stunt Plane. Parker shows signs of acrophobia and wishes for Douglas to land the plane. Suddenly, the weather begins to get murky and Harry Cane appears. He knocks Douglas out of the plane forcing Parker to overcome her fear of heights and pilot the plane. She is able to maneuver against Harry Cane's attacks and allows Jack to capture him. Douglas then returns and compliments Parker's ability to face her fears.
J.B. let Parker and Jack test drive the Doom Buggy while J.B. stands behind to help rebuild Douglas. However, Parker and Jack run into trouble when they encounter Trucker Dale, so they purposely dive into the ocean. Trucker Dale then attempts to use the Ghost Cannon to kill Parker and Jack, but it blows up and the cannon is launched into the air where it hits Douglas again.
Parker, Jack, and Douglas are inside Newbury Subway looking for Ghosts. They go after Rat Shaun who diverts Jack to one tunnel and Parker to another.
Parker encounters Rat Shaun and is able to capture him. Meanwhile, Jack runs into a train which reveals to be Dr. Drewell. He tells Jack that he's sorry and teleport him to the Hidden Side.
Jack ends up in the Hidden Side and gets into more trouble when Lady E. releases all of the Ghosts Jack captured. However, he is saved by a mysterious stranger who tells Jack that he is not alone in the fight versus Lady E.
Vaughn and Jack enter the school to look for Parker, believing that Parker can help them. Jack looks at the school through his phone, and observes that he can see the Living World with his phone's app. They find Parker running up the stairs to J.B., asking her if she has seen Jack, and she says that she hasn't. Parker continues down the hallway looking for Jack, but she is stopped by Mr. Clarke and made to go to class. Vaughn and Jack follow her and Jack tries to get Parker to notice him but fails until Vaughn tells Jack that he needs to truly scare Parker and Jack resorts to yelling her name, which works and Parker uses the Ghost Hunting app to see Jack and is shocked to find her great-great-great-great-grandfather Vaughn with him.
Vaughn and Jack arrive at a tree that they can use to escape the Hidden Side, while J.B., Douglas, Parker, and Spencer arrive at the same tree in the Living World. Parker and Jack use their phones to open a portal to the Living World, but then Lady E. and Axel Chops arrive at the tree and fight Jack and Vaughn for access to the portal. Jack and Lady E. end up coming through the portal, leaving Vaughn behind. Seeing that Lady E. is going toward the lighthouse, the Ghost Hunters follow her in that direction.
The Ghost Hunters travel toward the lighthouse: J.B. in her bus, Douglas in his plane, and Jack and Parker on boats. When they arrive, they find that Lady Evelina has already started to open up portals to the Hidden Side all over Newbury. Jack, Parker, and Douglas work together to defeat a Boss Ghost that came out of one of the portals, while J.B. goes after Lady E.
Jack and Parker get off of their jet skis and run over to the lighthouse to confront Lady E. When they reach the top, they begin to shoot at Lady E. with their phones. However, this only causes her light to go out, making it hard for them to see where she is. They try to shoot based on where her voice is coming from, but Lady E. is quick enough to avoid their orbs. She uses her powers to push them off the lighthouse.
Douglas flies his plane under them to stop their fall, but this causes the plane to unbalance and it crashes. J.B. and Spencer arrive and inboard Sweet Sally to see if they are okay. When they are, J.B. tells them that the only way to stop Lady E. is to cause Sweet Sally to explode.
Jack, Parker, and J.B. get in Sweet Sally. J.B. drives the bus toward the lighthouse, while Jack and Parker press all of the buttons. Then Jack and Parker go to the front of the bus, to shoot Ghosts out of the way. As they approach the lighthouse, everyone jumps out of the bus. It explodes in front of the lighthouse into Ghost-trapping energy, weakening Lady E.
J.B. captures Lady E. with her phone, but still is upset about the sacrifice of Sweet Sally. Then, a firetruck of firefighters show up, and she claims that the truck will be the next Sweet Sally. Meanwhile, Jack and Parker talk about what life will be like without having to hunt Ghosts, until Douglas reminds them that Ghosts are still coming out of the portals Lady E. opened.