Book 'Em is the third part of the 5th episode in season 2 of Dexter's Laboratory. Like its sister episodes, it aired on August 13, 1997. The episode features Dexter and Dee Dee trying to return a library book that was illegally checked out.
Dexter is in the public library checking out books for his report. Dee Dee appears behind him talking loudly. At checkout, Dee Dee inadvertently takes a book that Dexter didn't check out, Dexter impatiently orders her to move. At the lab, Dexter sees that the book Dee Dee had was not checked out properly, and he organizes a plan to get the book back in its place.
That night, Dexter and Dee Dee head back to the public library to return the book. Dee Dee lowers Dexter into the library with a rope, but she gets distracted by a butterfly and lets the rope go, causing Dexter to slam into the floor. Meanwhile, Dexter heads toward the check-out counter to find that it's blocked by infrared lasers. Just as Dexter puts the book inside the slot, Dee Dee sticks her head out. Fed up with Dee Dee's antics, Dexter yells out in the library and causes the silent alarm to go off.
Ms. L, the librarian, busts into the library with two thugs behind her and orders them to go after Dexter and Dee Dee. The siblings send the thugs on a wild chase throughout the library. Later, Dee Dee gives up on running and tells Ms. L she quits. Ms. L congratulates Dee Dee for catching Dexter. As punishment, Dexter had to read to several children and Dee Dee at story time.
Thug 1 & Thug 2 are a reference to the Dr. Seuss characters Thing 1 & Thing 2 from the popular children's story The Cat in the Hat.
Dee Dee is seen gliding along the floor, similar to Jaws from the Jaws film franchise.
A piece of music from the 1996 film Mission: Impossible is heard when Dexter grabs his agent gear.
The newspapers Dexter and Dee Dee are named "Times" and "Post", referencing The New York Times and New York Post.
The episode's title is a reference to the phrase "Book 'em, Danno!" uttered by Steve McGarrett from Hawaii Five-O.
The cover art for the Book 'Em episode credits the series crews' last names on the books starting from left to right: Renzetti, Miller, McCracken, Rote, Tartakovsky, Rudish, Castricone, and Desrochers.