This moment usually occurs at the 75–80% mark of a film or novel. It is indexed by three specific events:

In climate science and ecology, the "darkest hour" refers to a future or current tipping point. The indices here are measurable physical thresholds.

The phrase "darkest hour" has been used to describe a moment of great crisis or hardship, when all hope seems lost. For our planet, that moment may be closer than we think. The Index of the Darkest Hour is a theoretical concept that refers to the point at which the Earth's environmental degradation and ecological collapse become irreversible, marking the beginning of a catastrophic and potentially extinction-level event. In this article, we'll explore the concept of the Index of the Darkest Hour, its implications, and what we can do to prevent it.

takes us into the "smoky conference rooms and halls of power". Churchill, played in a career-defining performance by Gary Oldman