Made in Abyss is a spectacular anime, and the films also follow the same theme. The first film is a compilation of episodes 1-8, while the second film is a compilation of episodes 9-13, concluding the first anime arc, released in 2017. This is probably one of the best recaps I've ever seen, even though I've seen the anime and already know what's going to happen, the story is still wonderful and heartbreaking. Therefore, I recommend watching it even if you already know what is going to happen, as it serves as preparation for the 3rd film, where the really important events happened.