I would've appreciated more ambiguity. The resolution felt too convenient. Honestly the unravelling of the "mystery" which was only really relevant in like the last third of the book was the least appealing thing about the novel. It's really more about grief, identity issues and queerness in an age of repression. (Also the backdrop of the 2008 recession makes for a more compelling study of Hayley and Zoe and their contrasting financial positions).

Carbon monoxide poisoning fuelling Hayley's obsession with Beatrice and her mental degradation -- as well as Zoe's bulimia etc. was tragic. It felt inevitable and all the more upsetting because they were bound by fate to suffer these deaths, unable to escape the silent killer. I almost would've preferred it to be an accident and not the result of Beatrice's mother's meticulous planning.