Adams had intended to follow it with a third such novel, The Salmon of Doubt, but he died before completing it; an unfinished draft is included in a posthumously published collection of the same name.

The title is a phrase that appeared in Adams' novel Life, the Universe and Everything to describe the wretched boredom of immortal being Wowbagger, the Infinitely Prolonged, and is a play on the theological treatise Dark Night of the Soul, by Saint John of the Cross.

[1]While trying to purchase an airline ticket to Oslo at Heathrow Airport, American journalist Kate Schechter finds herself in line behind a large blond man who also wants to get on the flight but has no identification or means to pay.

At the private Woodshead Hospital, which caters to wealthy patients with bizarre medical afflictions, a one-eyed old man is removed and put into a van for transport to a new location during a visit by Kate.

Returning to her home, Kate finds the blond man - actually the Norse god Thor — waiting for her and in need of first aid after being glued to a wooden floor and attacked by a hostile eagle.

He discovers that the homeless persons sleeping in and around the St Pancras railway station are actually various gods whose status has declined drastically over the centuries, due to mortals' reduced need for them.

A BBC radio adaptation, The Long Dark Tea-Time of the Soul, starring Harry Enfield, Peter Davison, John Fortune[2] and Stephen Moore was broadcast in October 2008.