It was the middle of June. I had finished my school final exams and was waiting for the results to come out. Feluda and I were supposed to have gone to a film today, but ten minutes before we were to leave, it began raining so heavily that we had to drop the idea. I was now sitting in our living room, immersed in a Tintin comic (Tintin in Tibet). Feluda and I were both very fond of these comics which had mystery, adventure and humour, all in full measure. I already had three of these. This one was new. I had promised to pass it on to Feluda when I finished with it. Feluda was stretched out on the divan, reading a book called Chariots of the Gods? He had nearly finished it. After a while, he shut the book, placed it on his chest and lay still, staring at the whirring ceiling fan. Then he said, ‘Do you know how many stone blocks there are in the pyramid of Giza? Two hundred thousand.’ Why was he suddenly interested in pyramids? He went on, ‘Each block weighs nearly fifteen tonnes. From what is known of ancient engineering, the Egyptians could not have polished to perfection and placed together more than ten blocks every day. Besides, the stone it’s made of had to be brought from the other side of the Nile. A rough calculation shows that it must have taken them at least six hundred years to build that one single pyramid.’ ‘Is that what your book says?’ ‘Yes, but that isn’t all. This book mentions many other wonders that cannot be explained by archaeologists and historians. Take our own country, for instance. There is an iron pillar at the Qutab Minar in Delhi. It is two thousand years old, but it hasn’t rusted. No one knows why. Have you heard of Easter Island? It’s a small island in the South Pacific Ocean. There are huge rocks facing the sea, on which human faces were carved thousands of years ago. These rocks were dragged from the middle of the island, taken to its edge and arranged in such a way that they were visible from the sea. Each weighs almost fifty tonnes. Who did this? How did the ancient tribal people get hold of adequate technology to do this? They didn’t have things like lorries, tractors, cranes or bulldozers.’ Feluda stopped, then sat up and lit a Charminar. The book had clearly stirred him in a big way. ‘In Peru,’ he went on, ‘there is an area which has geometric patterns drawn on the ground. Everyone knows about these patterns, they are visible from the air, but no one can tell when and how they came to be there. It is such a big mystery that scientists do not often talk about it.’ ‘Has the author of your book talked about it?’ ‘Oh yes, and he’s come up with a very interesting theory. According to him, creatures from a