we all die in the end.
seriously. giving away minor plot details is not going to spoil the book for anyone.
unless it is, as I suspect, genuinely not that good of a book. in which case you might as well just read the spoilers and have done with it.
it's not like you could spoil His Dark Materials in the same way cos it's genuinely an ace bit of writing.
the knowledge that harry potter kills voldemort is not going to surprise anyone but the most blank-slate minded of readers.