Originally titled "The Sea Kings of Mars" when it first appeared in the pulp magazine Thrilling Wonder Stories and later rebranded for its publication as a novel, The Sword of Rhiannon is the story of Matthew Carse, a Martian archaeologist-turned-looter whose discovery of a mysterious tomb and a sword belonging to the dark god Rhiannon sends him hurtling back in time to a Mars ruled by corrupt imperialists, their tyranny backed by the super-science of sinister snake-men. In this world, only the Viking-like Sea Kings and their winged and aquatic alien allies dare challenge their oppressors, and with the discovery of Carse's sword, the time has come for a last desperate battle. Enslaved by the beautiful but evil princess of the imperial Sarks, and somehow tied to the dark god himself, will Carse help lead the rebellion, or find himself exterminated by his own allies? For more, check out the following excerpt:
Panting, dripping, his mind a whirl of confused speculations, he dug outward through the soft soil till a small hole of brilliant daylight opened in front of him.
Daylight? Then he'd been in the weird bubble of darkness longer than he had imagined.
The wind blew in through a little opening, upon his face. And it was a warm wind. A warm wind and a damp wind, such as never blows on desert Mars.
Carse squeezed through and stood in the bright day looking outward.
There are times when a man has no emotion, no reaction. Times when all the centers are numbed and the eyes see and the ears hear but nothing communicates itself to the brain, which is protected in this way from madness.
He tried finally to laugh at what he saw though he heard his own laughter as a dry choking cry.
"Mirage, of course," he whispered. "A big mirage. Big as all Mars."
The warm breeze lifted Carse's tawny hair, blew his cloak against him. A cloud drifted over the sun and somewhere a bird screamed harshly. He did not move.
He was looking at an ocean.
It stretched out to the horizon ahead, a vast restlessness of water, milky-white and pale with a shimmering phosphorescence even in daylight.
"Mirage," he said again stubbornly, his reeling mind clinging with the desperation of fear to that one shred of explanation. "It has to be. Because this is still Mars."
Still Mars, still the same planet. The same high hills up into which Penkawr had led him by night.
Or were they the same? Before, the foxhole entrance to the Tomb of Rhiannon had been in a steep cliff-face. Now he stood on the grassy slope of a great hill.
And there were rolling green hills and dark forest down there below him, where before had been only desert. Green hills, green wood and a bright river that ran down a gorge to what had been dead sea-bottom but was now—sea.
Carse's numbed gaze swept along the great coast of the distant shoreline. And down on that far sunlit coast he saw the glitter of a white city and knew that it was Jekkara.
Jekkara, bright and strong between the verdant hills and the mighty ocean, that ocean that had not been seen upon Mars for nearly a million years...