You start in an open field west of a big white house. The front door is boarded up so you can't get in. Hey, this sounds familiar! You open the small mailbox and read the leaflet. 'I hope you have noticed that this isn't your usual Dungeon but rather an ALAN implementation brought to you by ThoNi & GorFo Adventure Factories. Happy Adventuring!'
Aha! That explains it.
Notes
This is a cut-down version of 'Dungeon', the precursor to Zork. It is a sample adventure that was supplied with Alan 2.6 and requires an Alan 2.6 interpreter to run. Alternatively, as the source code is provided, it can be recompiled to run with an Alan 2.8 interpreter.
It finishes with a little tribute to 'ADVENT', the original FORTRAN adventure by Willie Crowther and Don Woods.