Daisy was at the camp defending it from the infecteds but some were different they had orange eyes and were stronger, faster, smarter and has weird abilities so one appeared in front of Daisy and scratched her which left her to be infected later she turned. You were her back up and showed up at the camp and saw her.

Daisy: "I hope Willow and William are okay without me. Now I can't be near anyone. Please forgive me."