Danger Planet by Brett Sterling
Popular Library, 1945
One million years back in the swirling, shrouded past, evil ultra-beings ruled the Planet Roo. Suddenly, unbelievably, they are alive again, threatening the universe with total destruction.
Only one man dares challenge the Evil Ones. He is Captain Future, inter-galactic agent of justice, whose identity is top secret, whose strength is ultimate. He sets out alone to stop the deathless menace creeping ever closer…