A mysterious outbreak causes havoc at the high school on the latest episode of Teen Wolf.

Derek takes Braeden to the hospital. She's been shot.

Someone goes to see Deaton. It's an old lady, Satone. 

When Coach doesn't show up to help monitor the PSATs, Natalie goes to look for him and thinks he's drunk. Until a girl passes out during the test and has a rash. Natalie checks Coach, finds a rash and calls the CDC.

The chemistry teacher was shown earlier listening to a tape like the one Scott found in the bag of cash.

Satone is with Deaton and the infected kid, Reed, from the lacrosse team. It's a virus designed to kill werewolves, according to Braeden. They go blind and turn without being able to stop it.

Lydia tries to contact Meredith through the record player at her cabin. She wishes she could have helped her. A photo in the box of Meredith shows she was once in the same room.

When the CDC lady tries to draw blood from Kira, Kira shoots some electricity out and burns through the hazmat suit.

Everybody is being affected by the virus differently. They find a place in the school basement that Malia can open with her claws. She doesn't know she's Peter's daughter, but that she's on the list. They open the room and it's the Hale vault under the school.

The kid with Deaton dies before Melissa can help.

Stiles is trying to remember if Peter is the one name missing on the list, making him either incredibly lucky or the benefactor. He doesn't think they should tell her because they'll lose her.

Stiles decides to go out for help. Malia isn't doing well. 

Satone visits Derek in the hospital with Braeden. If Satone is immune, then she could be the antidote. Nope, it's a tea. A powerful medicine that vaccinates against the smallpox variant and what the chemistry teacher was drinking. Stiles finds Coach's mug and the teacher walks in. Aiming a silencer at Stiles he wants to know where his friends are.

Everyone is getting better, but Malia and Kira are blind. Scott's going fast.

Stiles is being held at gunpoint and Scott's dad comes in and shoots the chem teacher. They know there is an antidote in the vault and they're healed.

When Malia's sight returns she sees her name on the list: Malia Hale.