The Fourth Riddle was created with Inform and has IFID 2C2E9DB6-49AE-478B-A7CC-BE443AF91A85. To play a work like this one, you need an interpreter program: many are available, among them Zoom
for Mac OS X and for Unix; Windows Frotz or Windows Glulxe for Windows.
Or you can play without downloading anything by following the 'Play In-Browser'
link, using the Quixe interpreter. You'll need to have Javascript enabled
on your web browser.
