"Let's see some insane rage put apples in those cheeks."

What would be the source of these insane rages?

His piercing blue eyes seemed kindled by an insane rage!

Then a kind of insane rage filled her face.

John was capable of insane rage, and during these times he would do things he later regretted.

Then the outcome of the race would depend on whether her terror or his insane rage was the greater motivating force.

Next moment, with a light of insane rage in his eyes, he sprang forward and struck Smith a heavy blow.

It was a male countenance, set in an expression, almost a mask, of insane rage.

Still, he had killed once in an insane rage.

She feared that he was about to burst into one of his insane rages.