Going back and forth between the books in this series and the TV show has been interesting for me. So far, I've watched season one, listened to the first book, watched season two, and listened to the second book. After the first book, one of the things that struck me is how much more time is covered in that first book compared to the first season of the show. More than five years pass in that book, while on the show, if I recall correctly, just one year of life at Brakebills passes. Certain events from the second season lined up with content from the first book, and some of what happens in the second book had me thinking, "Oh, right,that scene happened on the show in season one" Season one of the show followed both Quentin's and Julia's journeys, but in the first book, Julia mostly disappears, while the reader is in Quentin's mind. The second book follows both characters, and some of that season-one "Julia" material corresponds to flashbacks in the second book. Those flashbacks chronicle Julie's relationship with magic.
Early on in The Magician King, I was annoyed with Quentin. He was bored with his cushy gig as one of the kings of Fillory (his co-royals being King Eliot, Queen Julia, and Queen Janet. He was itching for a quest, and made a tax-collection trip that cost more than the amount of tax collected. He encounters a customs agent who mentions that she'd assumed Quentin intended to go on a quest for a very special key. That is not his intention since this is the first he ever hears of such a key. But the next thing you know, she is telling him pursuing the key would be a terrible idea. So I was irritated because Quentin of course decides this means he HAS TO pursue that key. However, things do not proceed the way I expected them to, and instead there is a hefty dose of "don't go on a quest for the wrong reasons." The right reasons for going on a quest present themselves as the story unfolds.
The character development of both Quentin and Julia interests me, and I look forward to the next book in the series. [Warning: one of Julia's flashbacks involves a disturbing rape scene--if you've watched the first season of the show, you have an idea as to what to expect.]