Dr Knowles and Professor McCork ask the question 'What is the world's most venomous animal?' and we learn that even some of the dangerous creatures can be very useful when creating medicine. Backstage, Colin sets up a super hi-tech security system to guard Ms Hucklebuck's top-secret office. Professor McCork and Dr Knowles won't take no for an answer though, and do all they can to break his code... but what lies behind the door?