The team are pitted against the villainous Kitty McHaig who has knowledge of a secret store of chemical and biological weapons.

Ed is in hospital after nearly being killed by Kitty McHaig. She is taking on a new identity, but the Bugs team are on to her, if they can decipher the password on Ed's plaster.

Ed and Alex are testing a new engine killer weapon when they are attacked and the weapon is stolen. Beckett is kidnapped by the thief.