Hammer of the Empire

They called me the Hammer of the Empire. I was a general who saved the country—and then became a threat. Now I’m a prisoner, doomed to endless confinement. But another threat has appeared—one against which the army and combat walking machines are useless. Then they remembered me. If I help, I’ll get my freedom and return what was taken from me long ago. And I have no doubt there’s a catch in this bargain.