Came up with the bassline after playing a lot of the bass to Public Image Ltd's "The Suit". Everything else spilled out, and after re-recording everything to be in-sync, I had this.
Originally I just did a constant loop of the bass, and it stopped suddenly, which gave me the mental image of a dead end or falling off a cliff. This quickly became someone giving directions and forgetting to tell the person that the bridge ahead was out.
