What are some of the literary devices used in And Then There Were None?

-I had to read And Then There Were None by Agatha Christie for my summer work, then answer that question, and I am completely lost. I know there is a plethora of devices that were probably used, I just can't put my finger on any at the moment. I need at least two specific ones. If you could just point me in the right direction I'd appreciate it. Thank (: