Ruth marries into a family, and all the men eventually die. Ruth's mother-in-law (Naomi) wants to go back to where she originally came from, and she encourages her daughters-in-law to do the same. But Ruth is totally (like kind of over the top) devoted to Naomi, so Ruth goes with Naomi to her home in Bethlehem.
Ruth goes to some guy's (Boaz) fields to follow behind the harvesters and pick up extra grain. Boaz is nice to her, tells her to come back and keep harvesting in his fields. And Ruth is SUPER grateful (again, kind of over the top, lol).
Ruth ends up marrying Boaz. This somehow involves Ruth sneaking into the threshing floor (where women are not allowed), and finding Boaz while he's sleeping and laying down near his feet. It apparently also involves some property that belonged to her dead husband – if Boaz buys the property, Ruth comes with it. Like some sort of toy in a box of Cracker Jack. Extra prize wife! It also involved Boaz assembling the town elders, and some ritualistic removing of sandals. All rather strange, if you ask me, but whatever.
Ruth and Boaz have a baby, but for some reason everyone acts like Naomi is the one who had the baby. I am so confused.
This baby is Obed, grandfather of David. David must be important, because we get a 9 generation genealogy.
That is the entirety of the book of Ruth. If anything of note happened other than “David's grandfather was born”, I'm not sure what it is.