You asked about sadness and what to expect. Giving you, or another, space to skip this post without reading, if you don't want to read it.
DH and I cried for about 10 solid minutes at the start. If you, or anyone you love and have empathy for, has had problems with having babies (or rather making babies), be WARNED, you will sob.
Then after that was done, DS wanted to run from the room because the main adult character gets really angry and acts out...DS just hated that moment.
There are poignant moments throughout. The dogs are really intense, and the owner of the dogs is just flat out evil, and scares ME (doesn't scare DS for some reason). But the end of his part of the story was still very shocking to me (even after I watched the special features where they discussed the options, I'm still shocked), but it's also very deserved.
And yes, it's alright at the end, but still poignant at the same time.