Marco returns to Mewni and is given a task to prove his worth as a knight in training.
Tropes:
- Blob Monster: The lint monster is entirely made of lint, and as such it can change shape, form tentacles at will and even when blown apart it can still reform itself.
- Determinator: Marco will stop at nothing to be a knight, even if it takes years, even if he has to be a squire for a knight with a seemingly thankless role.
- Fastball Special: Star blasts Marco over the lint monster to reach the industrial fan.
- Gender Is No Object: The royal guard of Mewni clearly doesn't discriminate between the sexes (let alone skin colors). Lady Whosits, an Ambiguously Brown amazon, appears to be their commander.
- Hypocrite: Star complains about Marco dropping into her life without any warning, seemingly oblivious to the fact that this was how the two of them first met.
- Knighting: Star gives the equivalent of a knighting ceremony to Marco, but to make him a squire.
- Mundane Made Awesome: Being a Knight of the Wash seems mundane and boring at first since it appears to be a glorified laundromat, but it is actually extremely dangerous. Doing something as simple as cleaning out the lint filter can get one killed, as a monster lives in the machine.
- Not So Above It All: Apparently Tom has a silly side too. He also sings into a burrito.
- Old Flame: Pun intended. Tom and Star are dating again, much to Marco's surprise.
- Shipper on Deck: Eclipsa. When she hears Star angrily complaining about how "some people" think it's okay to drop into your life without warning and don't appreciate your help, she smiles and asks "What's his name?", prompting Star to nervously tell her that it's not what she thinks. Eclipsa then makes a point of asking Star if she wants Marco to stay on Mewni.
- Strange Minds Think Alike: Star was singing a burrito song into a burrito before getting interrupted by Marco. Moments later, Tom comes out of the toilet, doing the exact same thing.
- Toxic Friend Influence: Eclipsa is already having shades of this by convincing Star that she can bend the rules to get ahead.
- Troll: The cape River gave Marco was actually fashioned from a meat blanket, so the whole "honorary knighthood" was just for humor.
- Unrequited Love Switcheroo: Played With. On Earth, Marco was dating Jackie, and Star developed a crush on him that he didn't return. In Mewni, Star is dating Tom again, and there are slight hints that Marco is confused about his feelings toward Star, but at least outwardly he doesn't really seem to care and takes this with a bit of a grain of salt.
- Weaksauce Weakness: The lint monster is almost indestructible, being able to pull its body back together when damaged, but can be broken apart and blown away by the lint catcher's fan.
