I got up this morning and, still half-asleep in the hall, spotted a brown streak on the wall above the internal front door. Fetched a chair to take a look to find a small slug resting on the lintel above the door and the brown trail wending it's wavy way a foot or so above it's resting place. There are no slug trails visible from floor or ceiling level; the mark starts above the lintel, from halfway down and right in the centre of the doorway.
We have an old house and so have double front doors, the external one and this internal one. We have occasionally have had slugs sneaking under the back door, with trails giving away their entry points, but never the front door so far. It's a total revolting mystery. Did it leap 7 feet in the air? Was it thrown by an invisible force? Did it somehow levitate its way up there? 