Paperback also includes 'A Dry Seed'.
He must not let anyone suspect that he was from another planet. That was Alan's most important order. To obey that order, he had to break all the others. He had to remain out of contact too long, he had to enter native dwellings and eat native food.
He soon found his training was nowhere near enough, and that nothing about this society was what it seemed. Instead of being primitive, the village teacher knew how many nucleotides it takes to code an amino acid in all five evolutions on this planet, how to amplify music pneumatically and a little about the thermonuclear reactions that go on inside stars. The expedition is frightened by what he finds and orders him back aboard.
But more than anything, the training did not prepare him for another thing he found on the study planet. He wasn't prepared for the power of love.