Dr Alice Roberts is put through a terrifying experience in the interests of testing how well her immune system will respond to threat. Only marginally less terrifying are the swabs taken by a microbiologist on a shared student house as Dr Alice is joined in her investigation into how the immune system works by a group of teenagers. They want to find out why they're so often ill ...could their party lifestyle and laid back approach to housework be a problem? Using all the means at her disposal - dissections, drawings, paint ball guns and even cakes... Dr Alice explains the fantastic complexity of our immune system.