Hangman's Rope
A 30ft length of rope. Fuses to whatever it is tied to, permanently. The rope is seemingly immune to all force. Nothing can undo its knots and it cannot be severed.
Sold by Mikhael the Merchant in Grift for a portion of the buyer's soul. Useful for bridges, anchors, prisons, and gallows; once tied, the world has a new permanent feature.
Connections
Gaps / Expansion Notes
A campaign of escalating knots — where the party leaves a permanent rope-trail behind them — is the obvious extension. Whether a Wraith or other ethereal thing can be tied with it is left for someone to find out.