Wiktionary
invisible rails
n. (plural of invisible rail English)
Usage examples of "invisible rails".
It was gliding down a steep entry path, as smooth as if it were mounted on invisible rails.
Fearless drifted forward at a mere twenty gravities acceleration, aligning herself perfectly on the invisible rails of the Junction, and Honor watched her display intently.
A flight of three ducks swept out of their pattern, extended wings to brake, and came sliding down invisible rails toward the fen.