SMG4: Smart Mario is the thirty-fifth episode of Season 9 and the five hundred and twenty-eighth overall to be uploaded by SMG4.
This episode was aired on September 21, 2019.
What would happen if Mario was actually smart?
The video starts with an advertisement for Saint Seiya. Then it has Luke Lerdwichagul transform into his video self before chasing after Mario who happened to be holding onto the phone with the game while still giving more explanation to what the game is about.
The actual video starts with Mario being tied up to an operating table. Shocked, he saw that Professor E. Gadd tied him up. As he was about to rat him out to his friends, a light came on revealing that they actually had him tied up to make him smart. Turned out that the previous day, Mario decided to rip out a heater and put it in his bathwater thinking it was too cold. Somehow, that caused the entire castle to burn down (as well as set Toad on fire). Mario pleaded with everyone to not kill him but they reassured him that they would only make him smart (even though Mario claimed he had an IQ of 10000) via E. Gadd's new machine.
One treatment later, the machine worked and after a few questions where Mario gave smart answers, they all headed back to the castle where it was still burning. Mario decided to fix the issue by building Robo Mario. He then went to help his friends, including unlocking Widnows 64 from SMG3 and returning the favor by banning him (causing him to jump off a building and commit suicide), fixing Meggy's Splat Roller, and helping Tari beat her opponent Bubble Bass at knocking the sandbag out by a huge margin in distance by typing in codes that would aid her.
Later on, after helping out, Mario felt hungry and decided to eat spaghetti for lunch. However, he still felt hungry and wanted more. He then looked at Luigi's lunch and wanted it for himself despite Luigi reasonably objecting to it.
Unfortunately, though the machine increased Mario’s intelligence, it still allowed him to act selfishly. Mario then decided he would build a machine that would allow him to steal all the spaghetti in the Mushroom Kingdom, the Spaghetti Succer 3000. The machine did its job well, even removing an Italian Restaurant that Bob Bobowski was planning to have his meal at.
As Luigi held onto the table, he was flown to where Mario was. With the angry mobs outside wanting their lunch back, Luigi pleaded with his brother to return the lunches but Mario said it was revenge for all the times he was treated like an idiot, saying that the old Mario was no more. Meggy missed the old Mario, as he was never able to throw tantrums at that scale. Just as Bob and SMG4 attacked him, Mario went in and unleashed a giant Robo Mario to swipe away the crowd. His friends then decided they needed someone as dumb as Mario to become the next subject of E. Gadd's machine. Bob asked where they were going to find someone that stupid, then wondered why they were staring at him, not realizing that HE was the stupid one.
In the Mushroom City, Mario was sucking in more spaghetti and was at 97% when suddenly, Bob's giant robot came up to challenge him. Mario accepted the challenge. At first, Robo Mario fired its punch but Bob evaded it and attacked Robo Mario with a gun. The damage caused Mario to panic and shoot him but it shot to the building with a television, causing corruption and changing into a TUBBIEtinder ad instead. Bob seemed to enjoy it, calling it intelligent, giving Robo Mario a chance to kick Bob to the ground. However, a Koopa Troopa, a Monty Mole, and Toadsworth were horrified at this. Bob then jumped and threw them at Robo Mario, causing Mario into a panic again and trying to take the three out via a screen wiper. Bob used this chance to decapitate Robo Mario's head.
Crawling out of the machine, Mario pleaded with his friends to not turn him back into his old stupid self, claiming he would lose his purpose in life, but they did not care and E. Gadd turned him back to his old self, and everyone was excited. Now knowing no one could stop him, Bob declared he was the best just to be also turned back to normal. The video ends with the camera rising into Bob after he made some dumb sounds.
The epilogue then showed Kevin, who sad due Luke's disappearance during Luke finds his phone, then Luke arrives at Peach's Castle and punches Mario when he played the game. Afterward, Luke returns to show an extension of the advertisement with Kevin and Luke reminding the viewers to download and play the app.