Original sentence: Hame explains that a "Bliss" drug created by the pharmacists wiped out the entire surface population, and only those in the Motorway were spared due to her actions to seal it off, keeping the travellers in constant traffic to avoid telling them the real problem.When Martha does so, the Doctor and Novice Hame are tending over the Face of Boe who is finally close to death
Edited sentence: Hame explains that a "Bliss" drug created by the pharmacists mutated into a virus that became airborne and wiped out the entire surface population, and only those in the Motorway were spared due to her actions to seal it off, keeping the travellers in constant traffic to avoid telling them the real problem.When Martha does so, the Doctor and Novice Hame are tending over the Face of Boe who is finally close to death; the glass container that encased it had shattered