The Plague of Silence

Dr. Palfrey becomes involved in a threatened world domination by an organisation that uses the forces of nature to obtain its will. The first signs are a woman found on the bathroom floor choking and convulsing. The Doctor attending her and his partner then die. A cloud of mosquito-like insects swarm and sting, paralysing their victims. How quickly is this spreading and can Dr. Palfrey act in time?