They say they feed on pure light but photons are just a part of their diet. They brought their nurse, and they attached it to the ceiling with large rivets. How the nurse feeds itself is a mystery they do not deign to explain. The nurse brings complements to them. According to our analyses, this seems to be a generic term for particles unconstrained by nuclear interactions. They must not leave it more than two or three hours. Though this restrains their mobility in our world, they firmly reject any project involving the transportation of the nurse. So long, they have started visiting anything worth the trip within a one hundred miles radius around the laboratory, and fortunately that includes our capital. They make few comments, and ask few questions, as if the sensory experience was enough for them. We showed them the Dome of Brunelleschi, the Ponte Vecchio, and they were treated with a VIP's express tour at the Uffizi Museum. After that, they demanded a painting of Botticelli, the Cestello Annunciation. We gave them a printed copy of it, that they hastened to display on