The Reckoning by Kelley Armstrong

      Chloe Saunders, a young but powerful necromancer who had the ability to raise the dead to be her zombies even when she's asleep, and Derek, an intelligence and protective werewolf had reunited with Simon and Tori, both of them are wizard and witch. Now, they are safe with Andrew, an old friend of Simon's dad, who's in the group of supernaturals who are working to fight against the Edison Group. But what they don't know is that Margaret, and Russell, also in the anti Edison Group, are working for the Edison Group to capture Chloe and her friends.

      Margaret and Russell killed Andrew and Gwen, a young witch who's also in the anti Edison Group. They captured Chloe and her friends back to the Edison Group's lab and they're about to get kill. But when Chloe got back to the lab, she met a spirit of a demi-demon who will help Chloe and her friends escape if Chloe agreed to free the demi-demon's soul, this is the only chance for Chloe to escape, but a demon is a demon and who might knows what will it do when Chloe frees it. Will Chloe be able to save her friends and escape this hell in the normal world? Read the book to find out! In my opinion, I think that this book is the best out of all three of the Darkest Powers series because it is suspenseful and it have an awesome plot.