At the horizon, a dark mass of clouds had begun to form.

The cloudy mass at the end of the bed began to take shape now.

But when the movies arrived, masses began to think in pictures.

At least two, because the glowing masses are beginning to spread apart.

As he approached, the vague mass began to take on definition.

Spock called out, and then the mass began to slide toward him.

The mass of people on the plaza was beginning to heat up.

And then, in defiance of any logic, the mass began to grow.

Pieces lay around him, and the main mass now began mere feet away.

It was then that the shadowy mass across the street began to move.