Edits

This puzzle is about the webcomic MS Paint Adventures, and particularly its long-running Problem Sleuth series.

The messages are strings of Problem Sleuth chapter titles; solvers can replace Chapter 1's title (Compensation, Adequate) with A, Chapter 2's title (Too Hot to Handle) with B, and so on (and counting the Epilogue as a twenty-third chapter) to get a series of commands typical of MS Paint Adventures. None of these commands were actually used over the course of Problem Sleuth, but each one sensibly could have been used in exactly one chapter:

PI: Use worthless scope to lever open crate.

The candy telescope is conjured into existence in Chapter 15, and the crate is thrown off the ship soon after.

AH: Professor Bee's speech is getting boring. Fast-forward him.

Professor Bee's long speech about JOCOSE HONEY is in Chapter 14.

PS: Perform Moonlight Sonata upside-down.

Problem Sleuth gets the Moonlight Sonata sheet music in Chapter 5, and the piano is destroyed before the end of the next chapter.

FPI: Chug the Merlot, then, if the others don't want it.

A one-off gag from Chapter 14.

AD: Juggle the three horns.

The horns in this case can't refer to the musical instruments from Chapter 4, since they were used up before Ace Dick could have had access to them. They must be the BURNISHED HORN, POLISHED HORN, and FERRUGINOUS HORN; Ace Dick only gains possession of them briefly before using them to make hot sauce in Chapter 9.

Mecha: Collect PANG NECTAR to use as fuel.

PANG NECTAR makes its first actual appearance in Chapter 14, though it was mentioned briefly at the end of Chapter 13. The candy mecha is destroyed in Chapter 14.

PI: Give PS some ILLICIT MOONSHINE.

Pickle Inspector and Problem Sleuth first meet on the material plane in Chapter 5, and Pickle Inspector dumps out his supply of ILLICIT MOONSHINE to make room for more ELF TEARS shortly thereafter.

MPI: Succumb to unfathomable bird's nest.

Monster Pickle Inspector only exists in Chapter 8.

NB: Remove sunglasses and marvel at the future.

Nervous Broad witnesses all future events at once as she's sucked into Black Hole Mobster Kingpin's event horizon. She's wearing Starsky's sunglasses at the time.

FAD: Eat jaw breaker bomb.

The jaw breaker bomb is summoned and deployed in Chapter 14.

AD: Throw dog at beast.

Ace Dick acquires the UGLY DOG in the imaginary plane during Chapter 4 and can be presumed to have lost it when the beast took his imaginary life a few pages later.

Patrons: HOOTENANNITECH -> MIDNIGHT SHINDIG

The stroke of midnight occurs in Chapter 18, prompting the evacuated speakeasy patrons to go back inside.

PI: Tie rope to handles of double doors.

Pickle Inspector first encounters the speakeasy's double doors in Chapter 5. He obtains the rope in this chapter and immediately uses it to solve the bust/oboe puzzle.

PS: Offer Stubbs, Jackson, and Fatts some coffee.

Problem Sleuth first reaches the painting room in Chapter 4 and consumes the last of the coffee before the start of the next chapter.

PI: React to cold blooded line with FRANKENSTEIN CRINGE.

Problem Sleuth delivers a particularly lame "cold blooded line" in Chapter 20, shortly before Pickle Inspector's GAMBIT SCHEMA: TOOTSIE ROLL FRANKENSTEIN wears off.

MPI: Succumb to unfathomable brain trust.

Monster Pickle Inspector only exists in Chapter 8.

PS: Heck, let's go nuts. Print entire walkthrough.

Problem Sleuth looks up the GameFAQs walkthrough and prints the cheat code in Chapter 9.

PFPI: Summon bowl of petunias to hammer reference home.

Zombie Ace Dick summons a sperm whale which is quickly killed and sent plummeting to Earth in Chapter 19. This is a homage to a similar scene in Douglas Adams's The Hitchhikers Guide to the Galaxy, in which a sperm whale and a bowl of petunias are created and dropped to the surface of a planet.

PS: Ride MAGIC WARDROBE like a mechanical bull.

Problem Sleuth only has access to the magic wardrobe for a brief period at the end of Chapter 6.

PPI: No, wait, erase solved sudoku so PI can have fun with it later.

Past Pickle Inspector solves the sudoku in Chapter 9, and dies shortly afterwards.

GPI: Throw lotus into breach in universe.

The universe is torn in half and repaired in Chapter 18.

AD: Caulk wagon.

Ace Dick and Bathearst are given the choice to caulk or ford while on the Oregon Trail in Chapter 19; he chooses the latter.

Higgs Bonehead: Fall in a more theoretical manner.

The Higgs Bonehead flings himself toward the NETHER-REGIONAL VULNERABULB in Chapter 20.

Converting the chapters to letters once again gives ONE NINE HUNDRED THIS FIRST. This is a reference to Madame Murel's business card seen in Chapter 1; the missing word is STRIP.