Faithful Companion was created with Inform and has IFID 12ECADA4-BE42-462F-8BD3-48FF623BEC6E. 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'
on your web browser.