Mayenne (Dumarest Saga 9), by E.C. Tubb, paperback science fiction novel
“The planet was without a star of its own. It was from another galaxy. It was uninhabited and it was sentient.
In its own way it might have been the most powerful single intelligent entity in the universe. But it knew nothing about humanity. So when it picked up the survivors of a wrecked space-liner, it was confronted by mysteries. What were men? What were women? What was emotion? What, especially, was love?
Whether any of the desperate handful could survive the devilish series of planet-wide laboratory tests the alien world devised to solve these mysteries would depend on whether any single one of them could answer such eternal riddles.
Dumarest – and Mayenne – thought they could.”