Ray Cummings

Overnight a mysterious tower sprang up in the city park - where there had been none. And a girl ran from it, seeking help. But the price of her rescue could mean destruction to that town not once but three times over. For the tower was a time-bridge that brought a tyrant's future metropolis face to face with a piratical colony of the past - to make today's city their battleground! One of Cummings' best works, The Shadow Girl remains thoroughly readable and enjoyable even though it was first published more than eighty years ago.