This particular adventure started last March, on a Thursday morning. By this time, Feluda had become fairly well known as a detective, so his number of clients had grown. But he didn’t accept a case unless it was one that gave him the chance to sharpen his remarkable brain. When I first heard about this case, it did not strike me as anything extraordinary. But Feluda must have sensed a great challenge, which was why he agreed so readily. The only other factor that might have influenced his decision was that the client seemed to be pretty well off, so perhaps he was expecting a fat fee. However, when I mentioned this to Feluda, he gave me such a glare that I had to shut up immediately.

The client was called Dinanath Lahiri. He rang us in the evening on Wednesday and made an appointment for eight o’ clock the following morning. On the dot of eight on Thursday, we heard a car stop and blow its horn outside our house in Tara Road. The horn sounded strangely different from other cars. I sprang to my feet and moved towards the door, but Feluda stopped me with a gesture.

‘You must learn,’ he said, ‘to play it cool. At least wait till the bell rings.’

It rang in a few seconds. When I opened the door, the first thing I saw was a huge car. Never before had I seen such a big car, except for a Rolls-Royce. The gentleman who emerged from it was equally impressive, though that had nothing to do with his size. A man in his mid-fifties, he had a remarkably fair complexion and was wearing a fine dhoti and kurta. On his feet were white nagras with an upturned front. In his left hand was a walking-stick with an ivory handle; and in his right hand he held a blue square attaché case, of a type which I had seen many times before. There were two in our own house—one was Baba’s, the other belonged to Feluda. They were handed out by Air-India as free gifts to their passengers.

Feluda offered the gentleman the most comfortable armchair in the living-room and took an ordinary chair himself to sit opposite him.

‘I rang last night,’ said our visitor. ‘My name is Dinanath Lahiri.’

Feluda cleared his throat and said, ‘Before you say anything further, may I ask you a couple of questions?’

‘Of course.’

‘First of all, would you mind having a cup of tea?’

Mr Lahiri folded his hands, bent his head politely and replied, ‘You must forgive me, Mr Mitter, I am not used to having anything except at certain hours. But please don’t let me stop you from having a cup of tea, if you so wish.’

‘All right. My second question is—is your car a Hispano Suiza?’