This book is very popular, and it deserves it! It does have some dark themes to it, like when the narrator tells you about " the secret". As for language, "damn" was used once, but that's all. Brian undergoes pretty intense stuff, like encountering a timber wolf ( the wolf ends up leaving him alone ) getting beat up by a moose, etc. As for sex, when the narrator tells you about the day Brian discovered " the secret", he says that Brian's mom kissed a man " deeply, with her hand on the man's cheek" refrencing tongue kissing. But, this is a GREAT book, and as long as you're 11 or older and you like survival/adventure novels, you should read this book.