After God abandons him, King Saul asks a witch to summon
the spirit of the recently deceased Samuel.
Remember the Urim? It was a contraption that was set into a magical vest that helped divine messages from God (or revelations). Well, the Urim wasn't working and Saul was getting desperate. So, he resorts to witchcraft - which is possibly an even bigger no-no than what Saul did wrong in the first place. If you remember, the reason why Saul's on Yahweh's shit list is because he failed to kill ALL of the Amelekites.
Saul requests of the which to summon the spirit of the recently deceased Prophet Samuel (whom this book is named after). Saul's reason for speaking with Samuel is because Samuel was very close to Yahweh. Well, the witch was able to summon a spirit who answered to the name of Samuel, but the spirit did not give Saul comforting advice. Also of interest, while she was summoning the spirit of Samuel, she reported to Saul that she saw gods ascending from the earth.
Samuel basically said, "Yea buddy, because of your little stunt sparing the lives of those Amelekites, Yahweh's basically going to hand you and all the Israelites over to the Philistines. But don't worry, you and all your family will be hanging out with me in the land of the dead by this time tomorrow."
Needless to say, this panicked Saul quite a bit.
While this was a sad chapter for Saul, there are a few interesting things we can take from this chapter. First, we can delve into the minds of the ancient Israelites and learn about how they divined information from their god(s). Secondly, the Israelite conception of a god is very different than the modern interpretation. They didn't believe in one god; they believed in many. This is evident from the witch's comment, "I saw gods ascending from the earth."
Even though she was a witch, the author and the ancient Israelites believed that though there were many gods; Yahweh was the most important of them. They were very much like a cult of Yahweh. It is from this belief of worshiping one god only instead of the others which monotheism would later evolve.