Doesn't this cover say it all?
The lyrics (in English) add some more nostalgy and fear, suggesting bloody secrets hidden under the purity of childhood. So, you have idyllic scenes lake this one:
Gentle dreams in fading blue
Summer dusk in golden green
Feeling turned to season hues.
And such disturbing pictures:
Rumbling waters underneath
Gleamed with many dizzy whirls my head spins
Bulging eyes staring at me
Chilled my spine, their spell holds me tight.
This composition requires a taste for classical inspired prog, but believe me when I say that it touches me each time I listen to it.