August Standalone BOTM Suggestions

[stu , Stupendous stuti {on hiatus}]

Hello everyone, according to the poll results the genre for the August Standalone BOTM is Mystery/Thriller.

-Please suggest only one book per person.
-The books should appropriate for all ages.
-It must be a standalone.

Please don't recommend books we've already read.

Suggestions:
The Dead and the Dark
League of Liars
The Cousins
You'll Be the Death of Me

[stu , Stupendous stuti {on hiatus}]

ny_the_bookworm wrote: "Truly Devious"

this is a series :))

[B , Bookish Bhavya {trying to be active again!}]

The Dead and the Dark

[stu , Stupendous stuti {on hiatus}]

League of Liars

[Willow Anne]

Ill suggest You'll Be the Death of Me