DOSA makes its most ambitious move yet: they're going to take over the Library itself, after meeting with Eve to determine the fate of the Librarians. Their knowledge is valuable, but DOSA is willing to let them go...if Eve helps with their hostile takeover.
- And the Adventure Continues: How the episode ends.
- Chekhov's Armoury: The love potion, Cassandra's new abilities, and Jake's "Gift of Inner Soul" from the Monkey King all play a part in defeating Apep.
- Double Reverse Quadruple Agent: Eve appears to side with DOSA to spare the Librarians, but in reality, it's part of a ploy that she and Flynn came up with to get Apep into the Library and destroy him with the Eye of Ra.
- Energy Absorption: Pure Evil feeds off the ley lines when released, and takes them with it when sealed again. No more worrying how to deal with that anymore.
- From Bad to Worse: Apep possesses DOSA's leader midway through, and attempts to blow up the Library to release pure evil. Just as Eve and Flynn predicted.
- Jerkass Realization: After all is said and done, the head of DOSA still considers the Librarians dangerous and wants to control the Library, but backs off when reminded how she set free Apep.
- Kansas City Shuffle: An odd variation is the way DOSA contains Jenkins; they know that the Librarians will figure out any problem, and purposely have the passwords be the exact opposite of the clues left behind, but the Librarians figure that out after a few failed attempts.
- Loophole Abuse: The Eye of Ra requires a mortal soul to eradicate pure evil, which sets up a Heroic Sacrifice...except that the Librarians use items from the season to give Apep the qualities of a mortal soul and sacrifice him.
- Paranoia Gambit: Eve convinces the head of DOSA that their methods to contain Apep are probably faulty. When DOSA's head disables security to check his sarcophagus, Apep possesses her, which was part of Eve and Flynn's plan.
- Taken for Granite: Jenkins is briefly petrified via Medusa's head, so that DOSA can capture him.
- Wild Goose Chase: DOSA attempts to send the Librarians on one, to take over the Library without incident, but the clues weren't aged enough to fool them for long.