Truth is, it’s been a long time now since I spoke to anyone. I am alone here, quite completely. I’ve made sure of that. The storm has been threatening all day and the lamp glasses are rattling in their frames – perhaps there is an earthquake shaking the foundations of my lighthouse. But I’m going to imagine instead a sea so warm it caresses my toes, a landscape of gently ribboned anemones and shoals of lilac-moon jellyfish, a glowing world of multicoloured coral where I wouldn’t have had to fight in the first place. That is where the indigo hamlets live. And now I’m going to finish where I started, with their story. Close your eyes, just for a moment. Forget how angry you are.

They leave their home ranges before sunset to search for a mate in the warm saltwater reefs of the western Caribbean. When they find a partner – and they find true partners – they wrap their transparent tails around each other and use their blue-white fins to swirl themselves through the sea. They turn together so close that their love dance spins the water into a vortex. It’s beautiful to watch: an extraordinary combining of colour and soft threads of DNA in the sheltered valleys between tall mountains of snowflake coral. They share, the indigo hamlets. They take turns. That is what makes them so special. They release alternating sets of gametes, male one moment and female the next, and it seems to me that they whisper the truth of how it can be. I want to join them but I can’t because suddenly I am back, transported against my will, standing in that room surrounded by the smell of stale chlorine. I have a choice and I must make it. I can walk away to live my life elsewhere. Or I can stay, and become a scientist. This is where the path splits. The world changes.

But now I hear the wind shaking the window glass and feel the air thickening around me. It is no use. The dense purple clouds have reached the black rocks and I made my choice a long time ago and I understand that the storm has finally—

Chapter 1

EVA OFTEN FELT that the entrance should be dilapidated in some way – paint chipped off, perhaps, windows in need of a clean. Nothing too dramatic, just a hint of changing circumstances. They had a local community group, though, like most neighbourhoods, and it was very well funded – her windows were cleaned regularly, fresh paint applied each year at the start of spring. Apparently it was more important to make sure the building looked good than to fund the work being carried on inside. It wasn’t even the government she was most angry with.