Like a cold, invisible shell, loneliness seemed to coalesce about him.

Worlds are protected from extraterrestrial interference by an invisible shell.

It danced in an unseen breeze, then sank and touched the invisible shell of the spell he'd cast.

Like feeling an invisible shell over the new one.

But that's exactly where the comets are born, in a great, invisible shell surrounding the Solar System.

He spent the rest of the flight sitting silently and expressionlessly in an invisible shell which not even Maura felt inclined to break.

"I imagined that these experiences had imparted something to my character, an invisible shell which would stand me in good stead", he wrote.

The deluge of their slugs had passed through the spreading sand cloud, the usually invisible shells illuminated by the medium.

She took a shaky breath and reached for the coffee-pot, an invisible shell of protective self-defence closing around her just in time.

The sound of the waves was always there, as if invisible shells were held to his ears.