The two triptychs, The Obscene Mystery and Untitled Triptych, and one autonomous stained glass artwork, Between Extremities, take Brian Clarke’s involvement in the Francis Bacon trials from 1998 to 2002 as their theme.

In his essay ‘Brian Clarke – traditions and discontinuities’ from The Journal of Stained Glass, Volume XXIX, Martin Harrison writes:

'The sombre triptych that memorialised Clarke’s ambivalence towards the Francis Bacon trials could be termed a modulator of darkness as much as light, since the majority of the picture field is occupied by sheet lead; against the negative black, the impact of the minimal colour passages is brilliantly intensified. The sole historical precedent for this system (and not once Clarke had in mind) is the extensive use of brown enamels favoured by certain Georgian glass-painters as a foil for dramatic chiaroscuro effects, but its renewal by Clarke is both a challenge to the imagination and a release of exciting potential.’