An inquisitive boy Suraj once went inside a railway tunnel in a jungle. In the midst of it he met a watchman, whose job was to watch the tunnel. He befriended that watchman, and together they drove away a leopard in the tunnel as the night train came along. A week later Suraj was on the same train as it passed through the tunnel. He was thinking of his new-found friend, who’d forever be invisible to passengers on the train.