It is night in the off-season town of Sagres and everything looks deserted, not a sound is heard.

Only...

Once in a while we hear a kind of murmuring, rumbling sound in the distance which we cannot define. Then we hear it louder and closer by but it disappears again.
The sound becomes stronger, still subdued, and all of a sudden very clear. A skater moves toward us, passes at very close range, moves around the corner and disappears.
Once in a while we still hear the rumbling sound but after a short time it is uttermost quiet again.