In the first 25 minutes we have a summary of the first season of the anime telling the main events, so before watching the film I suggest watching the season for a better understanding of the facts. After that we have the actual film in which our friend Goblin Slayer and his friends accept a mission to go after a nobleman's daughter who, upon becoming an adventurer, accepted a mission to hunt goblins. In the last act of the film, our heroes invade an ancient dwarf ruin that is filled with goblins, who are preparing for a macabre ceremony. Our heroes then show what theydo best, killing goblins.