She had heard of such invisible servants before.

The best computer is a quiet, invisible servant.

But the invisible servants did not deliver what he requested.

Inside he was given shelter and waited on by invisible servants.

They feast on large tables, served by partially invisible servants (only feet and hands are visible).

Umir turned and snapped out an order to an invisible servant.

She left the bathroom and entered the bedroom The silent, invisible servants had struck again.

It drifted across to Arthur, as if carried by an invisible servant.

So many invisible servants the air fair buzzed with 'em!

Another invisible servant made it vanish before she could snatch it back.