Obviously Sara Thornton must be dead by now, because a guy sitting on a train with no mask on obviously kills everybody around him, even they are all vaccinated and wearing masks, right?

Or maybe it didn't happen. Maybe the virus doesn't get spread by asymptomatic people sitting on trains. Maybe the virus has already spread to every corner of the planet, infecting all the low-hanging fruit. Maybe we never needed masks or lockdowns or any of it.