They threw themselves forward, but seemed to hit an invisible barrier.

It was as if she had an invisible barrier around herself that kept all others at a certain distance.

But he might as well have an invisible barrier about him.

"We were looking at ways to explore the invisible barrier between us."

He tried again, only to run into the invisible barrier.

And then the fire stopped, thrown back by an invisible barrier.

Only an invisible barrier still held the atmosphere inside the ship.

She tried to move forward, but seemed to be held back by some invisible barrier.

He could force himself forward a little but then it pushed back at him, this invisible barrier.

He put his hands out and felt the invisible barrier.