 Fearing the Mysterons' response to such an action, White orders Captain Scarlet and Lieutenant Green (voiced by Francis Matthews and Cy Grant) to investigate Red Deer.Arriving at the base, the officers discover that the personnel have suffocated not due to the introduction of a toxic gas, but the removal of all oxygen from the air.Obtaining a Spectrum Pursuit Vehicle from a trapper, Scarlet and Green speed to the next base, Big Bear, only to learn that Eddie has already passed through and is now on his way to the Frost Line command centre.