This was a cute slice of life episode. My favorite Twilight moments are when she's at her most adorkable and nerdy. Here we have her finding a book she borrowed from Canterlot library just before she left for Ponyville (MLP S01E01 "Friendship is Magic, Part 1"). Of course this sends her into a panic, because Twilight Sparkle is a perfect book borrower, and even has a plaque in the Canterlot Library stating as such. She flies back to Canterlot, Spike in tow, to return the book. Finding out she has the longest overdue library book on record, she heads to the subbasement ( "because of the shame!" ) to speak to First Folio, the current head librarian. Finding an out to lunch sign, she heads to Canterlot's restaurant row to find him.
After some searching, she finds Moondancer sitting with First Folio in The Tasty Treat restaurant (MLP S06E12 "Spice Up Your Life"). She discovers that Dusty Pages, Twilight's former head librarian was let go because her perfect record had been marred by a lost book. Twilight, horrified, leaves to find Dusty Pages home in Canterlot, only to discover that another pony now lives there. He tells her Dusty went to live in "Silver something" and that Twilight should also take her mail. Twilight, using a map, tracks down all of the nearby towns and places that have "Silver" in the name, finally locating a retirement community called "Silver Stable Community." She asks the receptionist where she can find Dusty Pages and heads to her apartment on the property. Getting no answer, she finds anypony who can tell where Dusty could be, finding out the mare has a busy schedule.
After some chasing and "just missed her" moments, Twilight catches her at band practice, shredding on an acoustic guitar. Twilight interrupts, but Dusty is thrilled to see her. Twilight brings her the missing mail, and fesses up to the lost book. Dusty is surprised, but when Twilight tries to get her to take the book and go back to Canterlot to get her library job back, Dusty balks. She doesn't want to hear anything about the Canterlot library again, and she leaves the room. Twilight is crestfallen.
In the next scene we find her sitting at the bar in a small club at the community center, with some jazz playing in the background. Twilight figures she's ruined Dusty's life, and her own record (Spike tallies up the number of bits she will owe when she returns the book, but ends up saying "you don't want to know," indicating the tally is enormous.)
Undeterred, she searches and finds Dusty Pages on the squishy fruit tossing field (something like paintball). Getting splatted while searching for Dusty, she calls out for her and the mare halts the game, but not before they've been splatted by flying fruit (which hits the book as well). When Twilight begs her to return and apologizes for ruining her life, Dusty realizes what has happened, and offers Twilight a seat next to her on a log. She explains that Twilight had it backwards: Dusty is thrilled to be free of the library, because she spent her whole career trying to be perfect. When Twilight forgot to return the book, Dusty saw it as the perfect opportunity to leave, and to actually live her life. In essence, she learned not to fear failure, and to accept that sometimes our failures teach us more than our successes.
She asks Twilight if she had even read the book, and Twilight blushes (which is so cute!), and admits she hasn't. Turns out the book is called "Perfection: The Impossible Pursuit." They laugh at the irony of the situation.
With this knew knowledge, Twilight returns to the Canterlot Library, and First Folio. When the late fee is tallied, Twilight offers to make payments, only to find out the total fine is 28 bits. Why? First Folio says they cap it at the first month (it would figure at that point you've essentially bought the book). She asks First Folio if she can keep it, as a lesson for herself, and First Folio mentions it has a stain. Twilight explains that it makes the book more symbolic. She hugs the book, and the episode ends.
Freakin' adorkable. This slice of life episode gets an easy A. I loved it.