Hi,
You have to have Demelza in your party at this point because you need
the Hamlet key to enter the Hamlet to drop her off.
If you are at the Marsh (25,16) facing south (should be a square with
stones you are standing on), there are the two red marks on the wall
where the false wall is. That should take you south into the
southeast corner.
If you email me your saved game file (Drg2SaveSSPD.pdb) to
cysk@... then I'll be happy to take a look at it for you.
Good luck,
Chris