The setting is on Raxter Island. It's the beginning of winter. The mood portrayed is restless because the girls barely sleep. The tox has kept their school under quarantine. They have to fight to survive.
There are three main characters throughout the story. They've all suffered the affects of the tox. Hetty goal is to follow quarantine rules because she is still hopeful for a cure to their disease. She's a sharp shooter and trusted my many. Reece doesn't allow many to get to know her. Ever since she lost her dad she didn't want anyone to be close. Byatt is the strong one. She is sure to find help any way she can.
The Initial incident is the parents sending their daughters to the all girls school off the mainland. The girls' main issue is to stay alive during the tox. The conflict is a external conflict. Man vs nature.