This is for demonstration purposes only! Comments welcome.
It is an attempt to implement the Cloak of Darkness, following the look used in the version created by the Pixie: http://docs.textadventures.co.uk/quest/util/cloak_of_darkness.aslx
As far as possible, the specification is followed precisely. Any assumptions made are listed. Type HELP and ABOUT for details.
The implementation also tries to make best use of what appear to be the most appropriate facilities in Quest. In doing so, a number of possible improvements to Quest are identified.