When a visiting American academic delivers a controversial speech, many audience members are worried that his ideas could be used to target ethnic minorities. Thus when he is found hanged the next morning and Dr Hobson quickly discounts suicide, Lewis and Hathaway realise they have many suspects - from the local anti-racism activist who was first in voicing her disgust at the professor's beliefs to the women who had bombarded him with threatening e-mails. But then another body turns up and the case takes on a new dimension.