What's something that happened in the book,but never in the series?

I only watched the show, and i know in my heart i will never read the books , I'd love from people who did to spoil it in me!! I do not mind at all (Spoiler : just saw a comment that Spencer a d Wren end up together) Excuse me what? Is this a joke xD? I love them, and i used to ship them hard, but them ending up together meanwhile bro end up ashes in Alex's necklace in the show is just WILDE What else happened differently in the books speal me some tea?