Death
The final horseman of the apocalypse is Death (though he is not the last of the apocalyptic signs). At first glance, he seems almost superfluous, with Pestilence, War and Famine preceding him.
I think the reason why Death comes last is that he is sovereign and self-determined. When apocalypse strikes, it’s already too late to look to the root causes of strife, aggression and apathy.
Only Death determines when he’s had enough. He will continue until he is sated. He must run his course. In the Book of Revelation we are told that he will continue until he has taken a quarter of living things, but we can expect that the mathematics of doom are not so precise or predictable.
This is bad news for consultants. It suggests that failing organisations have an intrinsic momentum to their cascade of failure that will resist any amelioration or cure. It needs to run its course, there is no single, simple thing you can do to fix it – or even multiple, complex things you can do.