The devil's breath - Tessa Harris

As a mysterious poisonous fog rolls over the English countryside, bringing death and destruction in its wake, Dr Thomas Silkstone uses his considerable skills to investigate why so many are dying in Oxfordshire and beyond.
Amid the chaos and confusion, however, Thomas soon discovers that the fog is not the only killer on the loose. As day merges into night, storms rage and meteorites tears across the sky, paranoia spreads like wildfire and many villagers believe the end of the world is nigh. It seems that no one, not even Lady Lydia Farrell, is safe from the impending doom.