"Rings are involved," Lucille confirmed, smiling. "So that is why everyone wears pins? I assumed they were just popular jewellery."

She sat down on the bench, arranging her skirts, and then, as Basnaaid disappeared to get the tea, she said to Tisarwat:

"I never expected to end up taking an interest in plants, and I certainly never expected to discuss the subject with a horticulturalist in a garden in space."

She added: "Do you know each other well?"