Milo participates in an annual race called "Race for Runts." He can't reach the finish line every year, but this time, he has Melissa and Zack carried his backpack for him, to help him with anything in there while he's running. Milo will also have his motivations for his friends, which come from his book of shark mantras. The race's finally begun. Meanwhile, Brick and Savannah are having their protecting pistachios mission at the finish line, and Cavendish and Dakota are planning to muck that mission up. They meet Milo running the race, but unfortunately their time-travel vehicle brings them back to the 1870s. They try to come back, but a horse kicks on their car, and they're forced to stay for a while.
In the middle of the race, Milo tries to have some water, but unable to. At a bridge, Milo tells them to throw the discus to the bridge control system, but Melissa can't, so she throws a stuffed elephant instead. Milo also needs a bandage because he has a blister. Meanwhile, when Dakota enjoys his stay at a tailor shop, Cavendish's trying to figure out how to fix the time machine, stop Brick and Savannah from protecting pistachios. A Sheriff suddenly comes, reveals himself as a Murphy's Law man. He also tells Cavendish and Dakota that there are more time travelers in this Old West. Cavendish realizes this is a chance to repair their time machine.
At the race, Milo comes in front of an overpass demo street. Melissa and Zack try to find things in Milo's backpack that could help him, but they can't. Milo then takes out in his backpack a long pillar so he can jump through. Meanwhile, at a saloon in the Old West, there are lots of time travelers who stuck here. One of them says the person he knows, personally, who's really from here is Sheriff Murphy. Cavendish then jumps to conclusion that he's the original Murphy's Law - Milo's great-great-great-great grandfather. His appearance also makes this Old West a time-travel Bermuda Triangle, so that a bunch of time travelers get stuck here. Their time machines can't be used also, because they're running out of fuel.
Cavendish and Dakota try to start the engine of their time machine, but can't. They then push it to the time-machine junk yard to figure out an idea later. But with the help of the Sheriff, the horses are out of control, push their car faster. Dakota realizes that this could help the engine works. They've finally done it, but then they reach to a high cliff and fall in the air. Dakota uses the time-travel mode to save him and his partner from the death. The Sheriff also tells them to say hi to his great-great-great-great grandkids.
The race almost comes to an end. Melissa and Zack, once again, try to find out things that can help Milo, but can't think of anything. They suddenly come up a same idea when Zack says "finished". The protecting pistachios mission is still safe and sound, until Cavendish and Dakota's time machine appears from the sky, destroy the pistachio cargo. They're happy when they finished "their mission", but the time machine drags the finish line away, and Milo's so close to finish the race. However, his two best friends have done a backup finish line. They have helped Milo with everything in Milo's backpack, while Brick and Savannah are upset with their first protecting pistachios mission failed.
- "Weird Al" Yankovic as Milo Murphy
- Sabrina Carpenter as Melissa Chase
- Mekai Curtis as Zack Underwood
- Jeff "Swampy" Marsh as Balthazar Cavendish
- Dan Povenmire as Vinnie Dakota
- Ming-Na Wen as Savannah
- Brett Dalton as Brick
- Diedrich Bader as Sheriff Murphy
- This episode takes place after "Perchance to Sleepwalk", when Brick and Savannah have their first protecting pistachios mission, while Cavendish and Dakota try to muck it up to prevent the pistachios dominated future.
- Melissa is shown again that she isn't good at throwing. ("Athledecamathalon")
- The original of Murphy's Law is a Sheriff.