Again she watched his truck fade away into the darkness.
You can watch the woman who brings sunshine into every room fade away like the sunset.
A band might in that case fade away towards zero frequencies, and as s increases, return again from infinity with diminishing distances, the head and the tail pointing in the same direction; or with a different value of constants a band might fade away towards infinite frequencies, then return through the whole range of the spectrum to zero frequencies, and once more return with its tail near its head.
Some wines get better with age, while others fade away.
Notes on a piano produce a fixed sound when played which do not go up or down but gradually fade away.