WARNING: This is an episode that premiered in a country other than the US, so if you don't want to be spoiled, we advise you not to read the synopsis. If you do, it's your risk.
In the Loud House, Lincoln is showing his family some of his magic tricks. As a bored Lola looks out the window, he spots Mr. Grouse holding a fancy ring, and runs over to him. Approaching Mr. Grouse, who is holding a metal detector, Lola asks where he got the ring, and Mr. Grouse tells her that he found it. He says he's participating in a precious stones and metal show tomorrow, and is trying to find enough valuables to make a lot of money. Being a money person herself, Lola requests to join him, but Mr. Grouse says that he works alone. Because of this, Lola decides to consult Lisa on turning her Jeep into a treasure tracker.
At Tall Timbers Park, as Mr. Grouse searches for more precious metals, Lola arrives in her souped-up jeep, now with metal detectors. After showing Mr. Grouse her sack of metals she collected, an angered Mr. Grouse declares that two can play at that game. Throughout the day, the two fight to claim areas to search. Tired of confronting each other for every area they search, Mr. Grouse decides that he and Lola will search their own half of Royal Woods. Later, as the two arrive to Scratchy Bottom Beach, Lola and Mr. Grouse detect something nearby and race to get it. Upon confronting each other, the two start digging, and they manage to find a precious giant diamond. As the two argue over who really owns it, Flip arrives to tell them the diamond sits perfectly on the middle, meaning they both possess it. The two agree to watch over the diamond together until the show tomorrow, but when they can't decide who should watch over it, Flip also suggests that they take turns.
At Mr. Grouse's house, as he examines the diamond, he quickly runs off to use the restroom. As Lola looks on from her house, she sees that Mr. Grouse has left the diamond unattended, and orders Walt to retrieve it. Walt succeeds in nabbing the diamond, just as Mr. Grouse arrives back to discover the diamond gone. Seeing that Lola took it, he uses a fishing line with a plunger to take it back. When Lola discovers that Mr. Grouse took the diamond back, Lola admits that taking turns won't work. She decides to bring in a glass case so they can watch it together, and Mr. Grouse decides to add some extra protection by wrapping a chain around it and swallowing the key. Throughout the day, the two keep a close eye guarding the diamond, slowly getting more and more tired.
The next day, Lola wakes and discovers the diamond is missing. Lola attempts to search Mr. Grouse, but he wakes up and discovers the diamond gone. The two quickly accuse each other of stealing the diamond for themselves and proceed to go on a rampage to find it, destroying each other's houses in the process, like Mr. Grouse using a jackhammer on the Loud's front lawn or Lola trashing Mr. Grouse's living room, and towing his fridge through the front door. As the two begin to accuse each other of stealing the diamond again, Lincoln reveals that the diamond was still in the case this whole time; it was one of his magic props, and it had a false bottom, so at one point, the diamond slipped through the cushion. Realizing they fought for nothing, Lola and Mr. Grouse apologize to each other and decide to go to the precious stones and metal show to sell the diamond and collect their earnings.
Later, Lola and Mr. Grouse arrive back home with their stacks of cash. However, Lynn Sr. takes away Mr. Grouse's half of the earnings in order to pay off for the damage he caused to his house. As Mr. Grouse admits that he deserved it, Lola, feeling bad for him, decides to relinquish her half of the earnings to pay off the damage she did to his house. After thanking her, Mr. Grouse tells her that not all of the money needs to be spent on repairs, saying that they can buy ice cream. Lola agrees, and the two admit that they make "a really good team."