A new type of food called Phodex has been created and it is made from some sort of algae. Ros, Ed and Beckett are called to investigate about this stuff, and Ros ends up getting trapped in some room, with the oxygen levels slowly decreasing. However, Ed and Beckett realise all is not right when the creator of Phodex tells them that Ros has gone to the hairdressers. They find her just in time and she is OK. However, a short while later, the team find out the secret of Phodex, that it is toxic when exposed to ultra violet light, and Ros ends up eating some contaminated Phodex, and starts to die. There is soon a race against time for Ed and Beckett to save Ros and the other people who have eaten the toxic Phodex, and Ros' condition gradually begins to deteriorate, as her vision goes blurred and she keeps collapsing. However, she manages to save the day, by finding out what the code is to the place that has the antidote. She has to read an electronic organiser, but will she get the passwor (thetvdb.com)