After the events from the first book (The Magicians) Quentin Coldwater and his friends are now the rulers of the magical land of Fillory. Feeling restless Quentin embarks on a quest at the first opportunity, seeking seven magic keys that are vital to the land.
He and his friend Julia sail across the seas on his quest. When one of the magic keys transports them back to Earth without any way to return they end up on a journey through the underground magical world on Earth in an attempt to find a spell that can take them home to Fillory.
Along the way they discover that there is a deeper peril to magic itself connected to the quest for the keys. They team up with an old friend from Brakebills and an Australian magician named Poppy while tracking down a magic button that will allow them to travel between worlds.
A large portion of the book deals with Julia's backstory, revealing how she became a magician herself without the assistance of a formal education at Brakebills. She becomes his guide through the dangerous world of underground magic practitioners that operate outside of the formal rules of magic followed at places like Brakebills, and often are at odds with those authorities.
Best part of story, including ending:
Julia's backstory is dark and fascinating, and the idea that there is a whole world of magicians outside of the elite that get into Brakebills makes a lot of sense.
Best scene in story:
When Quentin and his crew attack a castle and he has his first real taste of warfare. The description of the adrenaline rush, the emotions going from fear to rage to regret are very vivid.
Opinion about the main character:
Quentin is still a young man, and shallow at times, but he has grown up a bit and grows further as he spends more time looking outside himself in this book.