PROLOGUE

Like every early evening, I walked through the gardens. White, yellow and even red roses closed their flowers and prepared for sleep, as did most citizens of London and the whole of Great Britain.

I walked to the farthest corner of the gardens and looked at a bunch of black roses. Again, like every other day, I recalculated them.

Then, however, I was frightened and forced to recalculate them once more. And really. There were only five, not seven.