Ghostwatch: Behind the Curtains

Greetings, Ghostwatchers. Every so often, something surfaces from the depths of Ghostwatch folklore that refuses to stay buried. That makes you question whether any of this was ever really over. Back in the spring, I received a standard saved search email through a small UK auction site for a listing that, at face value, didn't seem to align with any of my saved searches... a small batch of BBC Engineering floppies under the disarmingly mundane listing: "Broadcast Ops (Assorted)". The thumbnail showed a handful of 3.5-inch 1.44 Mb disks, their handwritten labels half-faded and curling. In the item description, "Vintage computer disks. Estate clearance. Untested." As you can see, six 3.5" floppies. Nothing unusual, save for one - a single disk which, despite being partially obscured, I somehow knew was marked GHOSTWATCH.EXE - and in red biro on the reverse side, "DO NOT MOUNT." At first, I assumed it was another of those clever fan projects or ...