Eliot and Margo are going to Ibiza. It's basically Brakebills Spring Break and in order to go, one has to be invited and bring a gift for the elders. So they have an underclassman (Todd) begging them for an invite and a plan to make magic gin to present to the elders.
Meanwhile, Julia's sister arrives to check in and take care of her. And why wouldn't she? To the world, Julia appears to be a drop out who sought fake treatment for pills. Even worse news? Julia's mom could probably have her committed very easily.
Mayakovsky tells the team that they have to learn mind-control on lesser creatures. And also, he realizes that Penny is a traveler and now wants to help him by cutting off the tattoo that binds him to Earth.
After Penny embarks on some traveling, and survives even landing in a volcano, he decides to patch things up with Kady by reading her mind and learning all about her. He decides to steal something from Mayakovsky so that she can buy her freedom from Marina.
Eliot and Margo's plan to conjure magic gin actually turns out to be a plan to conjure a magic Djinn. So. A genie. And since it was Margo that conjured him, the Djinn reads her mind and makes Mike, Eliot's new beau, disappear.
It turns out that the wish Margo made in her head was for Mike to go "find another knob to suck on." And so, quite literally, that's where they find him. After Eliot scolds her, Margo, reluctantly, wishes everything back to normal.
Bad news all around. After Kady had to drop her brain charms so Penny could read her mind, Mayakovsky learned about how much she'd been stealing. And so has Brakebills. She's been expelled and that means when she gets back, her memory will be wiped. Instead, she leaves Brakebills South and dumps Penny by a note. It's tragic, when you think about it - Kady chose to remember loving (and losing) Penny than not remembering him at all.