I'm sure I had a blank expression on my face, but my brain was whirring.

"That's what I hoped you'd say," Sean murmured, and his brain whirred as he estimated times and distances.

He stared back, and his brain whirred.

Her brain whirred again, that starter-motor turning over sluggishly and just managing to fire; only just.

She lay back and closed her eyes, but her brain was whirring too much to sleep.

Buchanan could almost hear her brain whirring.

And suddenly, too, her brain was whirring.

His brain was whirring.

Thurston's brain whirred with the precision of a fine chronometer, buffered against panic by the sheer shock of what had happened.

Ronni could see that Guido's brain was whirring.