‘Feluda,’ I said, ‘in this whole business of blue cases and jumping hooligans, what strikes you as most suspicious?’

‘The newspapers.’

‘Er … would you care to elaborate?’ I asked hesitantly.

‘I cannot figure out why Mr Dhameeja folded the two newspapers so neatly and put them in his case with such care. A newspaper, once read, especially on a train, is useless. Most people would leave it behind without a second thought. Then why …?’

This was Feluda’s technique. He would begin to worry about a seemingly completely irrelevant point that would escape everyone else. Certainly I couldn’t make head or tail of it.

In the remaining hours that we spent in Delhi, two things happened. The first was nothing remarkable, but the other was horrifying.

Lalmohan Babu turned up at about half past twelve. We decided to go to the Jantar Mantar, which was not far from our hotel. Jatayu and I were both keen to see this observatory built two hundred and fifty years ago by Sawai Jai Singh. Feluda said he’d much rather stay in the hotel, both to keep an eye on Dhameeja’s attaché case and to think more about the mystery.

The first incident took place within ten minutes of our arrival at the Jantar Mantar. We were strolling along peacefully, when suddenly Lalmohan Babu clutched at my sleeve and whispered, ‘I think … I think a rather suspicious character is trying to follow us!’

I looked at the man he indicated. It was an old man, a Nepali cap on his head, cotton wool plugged in his ears, his eyes hidden behind a pair of dark glasses. It did appear as though he was interested in our movements. How very strange!

‘I know that man!’ said Jatayu.

‘What!’

‘He sat next to me on the plane. Helped me fasten my seat belt.’

‘Did he speak to you?’

‘No. I thanked him, but he said nothing. Most suspicious, I tell you!’

Perhaps the man could guess we were talking about him. He disappeared only a few minutes later.

By the time we returned to the hotel, it was almost half past three. I asked for our key at the reception, but the receptionist said he didn’t have it. This alarmed me somewhat, but then I remembered I had not handed it in at all. It was still in my pocket. Besides, it was rather foolish to worry about the key when Feluda was in the room to let us in. ‘Just goes to show you’re not used to staying in hotels,’ I told myself.

Our room was on the right, about thirty yards down the corridor. I knocked on the door. There was no response.

‘Perhaps your cousin is having a nap,’ remarked Lalmohan Babu.

I knocked again. Nothing happened.

Then I turned the handle and discovered that the door was open. But I knew Feluda had locked it from inside when we left.