The discovery of two skulls at the site for a new by-pass road leads the team to a pharmaceutical company. Someone doesn't want the skulls identified and will go to any length including murder.
Doctors treat Professor Hutton with anti-venom, but it's not enough, and the killer claims a second victim. An expert snake handler is called in to assist The Police.
The killer strikes again, another staff member from Casco is targeted, only this time Mike is on hand to deliver anti venom to the victim. The hunt for the killer begins.
Racial violence or something more sinister? The Taggart team are baffled by murders with no connection other than a possible racial link. Or is it something not so obvious to the all seeing eye?