On The Magicians Season 4 Episode 13, Penny saves Julia but has to make a difficult choice, Quentin and Josh visit the realm of The Old Gods, and Kady saves the day with the help of the hedgewitches.
When you watch The Magicians Season 4 Episode 13 online you'll see Penny save Julia from The Monster with the ice axes, but since Julia's body is weird she can't heal on her own. The Binder can help but he needs direction as to whether he should turn her into a goddess or make her a human. Penny choses human. Meanwhile Kady and Zelda get treatment for their Poison Room venture and Kady demands that Zelda prove that she's not as obidient as she appears. Josh is no longer a fish, and now has some serious fish magicks which he abruptly loses because this plot seems determined to not give the Brakebills students anything useful to work with. Kady's alliance with the hedgewitches comes in handy with the ambient magic low though since they will need a lot of people to cast and incorporate bond until The Monsters can be disposed of. While in the mirror universe getting ready to throw the bottles into The Seam, Everett shows up and breaks the mirror. But Quentin's discipline is mending small objects, and he's able to fix it, but the act of casting causes magic to ricochet and kills him and Everett. In The Underword, Penny meets Quentin at the elevator and is ready to sheperd him through the afterlife. Quentin sees his friends grieving over a fire where they burn momentos of him including a peach, his Brakebill's enrollment, playing cards, and his first edition Fillory book.
On The Magicians Season 4 Episode 13, Quentin and Josh get cake, while Quentin reflects on his actions during the season finale, "The Seam."