At the top of the stairs

 is a Sunless Sea Story Event.

Trigger conditions
 is triggered when you do the Make a delivery action in the DELIVERIES story event.

Story description
"You have: a long heavy box; a winding path ahead that runs perhaps a quarter mile through the mist; a crew that is beginning to mutter about having to do landlubber work.

''There's a warehouse just to your right, but the sign says deliveries are to be taken onward. Says it rather emphatically, as a matter of fact."''