They put an invisible curtain around the tanks.

When he spoke, his words seemed distant, obscured by some invisible curtain.

It was like an invisible curtain closing down upon every side.

After that, he was careful to knock on doors, to draw an invisible curtain of distance around her for privacy.

It was like passing through an invisible curtain of hot air.

It was as if some invisible curtain hung there.

Her eyes seemed to clear as if, with Sam's name, some almost invisible curtain had been raised within them.

The cart passed through an invisible curtain and emerged at the carnival grounds.

Iris's chatter seemed to break an invisible curtain of suspense.

It was like walking through some sort of invisible curtain from late fall into deepest summer.