The story of Samuel begins with, funnily enough, the birth of Samuel. After being raised by the priest Eli in temple, Samuel becomes God's number one prophet. Up until this point in biblical history, the Israelites have not had a king. Tired of not being able to complain about what a lousy job their king is doing, Samuel (after some anointing by God) sets out to enlist a king for Israel. Sounds simple enough.
He chooses a man named Saul, and it turns out he chose… poorly. After Saul mucks up with the Philistines a few times and fails to unite the tribes of Israel together, God sends Samuel to find a new king—a better king. It's a good thing Samuel didn't have much else going on.
After more searching, Saul settles on a young boy, David, the son of Jesse. After some scheming, David travels to the palace. Saul becomes infatuated with David (in a non-creepy way) and David becomes Saul's armor bearer. This would be akin to a squire in a medieval court. David's main skill in court is to soothe Saul's head demons (headaches) with his lyre and his mad musical skills. Personally, we prefer a kazoo, but what can we say, we're Shmoop.
Now, all over the un-united kingdoms of Israel (you had one job, Saul), the ravaging armies of the Philistines are causing chaos. After some skirmishes, the Philistine champion (and supposed giant) Goliath makes an offer: a one on one death match to determine the winner over the war. Every Israelite says "no thank you" and politely declines his generous offer.
David, fed up with people's cowardice, steps forward to fight Goliath. Having faith in God in spades, our David doesn't fear death—or the giant for that matter. Goliath, being, well, dumb, removes his helmet and charges at David. The boy king sends a rock flying into Goliath's skull, instantly killing the monstrosity of a man. All of Israel rejoices as David removes Goliath's head from his body—for good measure, you know.
After defeating Goliath, David becomes insanely popular which sends Saul into fits of jealousy and rage. Saul attempts to murder David several times over the years as David amasses more and more power and support of the Israelites. Eventually, David flees and becomes a double agent for the Philistine army. At the end of the book, Saul and his sons are killed in battle against the Philistines and David is ready to become king.
Then it's time for the sequel.