At Annies house they all realise that the Taint is coming from Denise. She suffered from bloodpoising since she was bitten by a rare spider on a Greek Island. This bloodpoising gave her the sweetest blood. Vampires are unable to resist, however Denise did not know that at that time. After she came back to England Denise went to see Dr Declan McGough. He gave her a medicine and told her this is going to destroy the virus. However it wasn't going to destroy the virus, it made the virus stronger so that it took all over her body. Dr Declan McGough wanted to create a new weapon with her blood against vampires. He wanted to mix Denise's blood with the blood of Leo Willis who was immune to vampires. If vampires drank Leos blood they would have died. Mixed with Denise's blood it would make it imp