That afternoon, in Panditji’s house, Byomkesh was half-reclined in an easy chair, telling the story. The listeners were myself, Panditji, and Ramapati.

“I’ll be brief. If I leave anything out, ask.”

Panditji said, “Let me say something first. That white powder you asked to have tested—the chemist’s report has arrived. Here, take a look.”

Byomkesh read the report, his brows knitting. “Sodium Tetra Borate—Borax, that is, Sohaga? What is Sohaga used for? I know one thing: gold and Sohaga. Is it used for anything else?”

Panditji replied, “I’m not sure. Perhaps in those days it was used for making medicines.”

Returning the report, Byomkesh said, “Well. Now listen. Manilal appeared to be a decent man on the outside, but his nature was that of a demon—cruel and greedy in equal measure. After his marriage, he resolved to seize his father-in-law’s entire estate. He received no kindness from his brothers-in-law, nor did he love his wife. Only his father-in-law did he win over with gentle words.

“Manilal’s first opportunity came when a group of Bedes set up camp nearby. He secretly obtained snake venom from them.

“It’s not immediately clear why he killed his wife first. Perhaps, in a moment of weakness, he revealed his intentions to her, or perhaps Haripriya herself witnessed the process of filling the pen with snake venom. In any case, Haripriya had to be removed first. But that created a major problem—his connection to his father-in-law would be severed. Yet Manilal had so thoroughly ensnared his father-in-law that he was confident Ramkishore would not break ties with him. His eyes were already on Tulsi.

“In any case, after Haripriya’s death, there was no trouble; the match with Tulsi was all but settled. Manilal waited patiently, planning to remove his brothers-in-law one by one once the relationship was confirmed. Two years passed; Tulsi was nearly of marriageable age when Ishan Babu arrived. Not long after, the holy man appeared. There was, of course, no connection between these two; neither ever realized how close he was to his old friend.

“Ramkishore Babu carried the shame of abandoning his brother to die. Recognizing the ascetic, his heart gave out—he was on the verge of collapse. After regaining some composure, he said to his brother, ‘What’s done is done, but if the truth comes out now, I’ll be utterly disgraced. Go to some pilgrimage site, build a monastery, stay there—I’ll provide whatever funds you need.’ But Ramvinod had his brother in his grasp; he would not budge. He sat beneath a tree, cursing his brother.

“That’s my deduction. But if Ramkishore ever tells the truth, you’ll see I’m not wrong. Manilal, however, was thrown into great difficulty by his father-in-law’s illness; if the old man died suddenly, all his plans would be ruined, and the brothers-in-law would throw him out at once. He began advising his father-in-law to separate the two elder sons. That way, if Ramkishore died of heart failure, as guardian of the minors, Manilal would gain control of half the property.”

The Mystery of the Fort

After that, he would marry Tulsi, and Gadadhar would die of snakebite.

"Manilal was trusted implicitly by Ramkishore; besides, Ramkishore himself feared that after his death, his two elder sons would deprive the younger siblings. He agreed; discussions with the lawyer began.

"Meanwhile, another incident was unfolding at the fort; Ishanbabu was hunting for hidden treasure. First, he found the Persian inscription carved on the mat. He carefully copied it into his notebook and began his investigation. Then, while fiddling with a spike in his own bedroom, he noticed a stone was loose. It didn’t take him long to realize that beneath that stone lay the fort’s treasury.

"But the stone was massive, heavy as a mountain; Ishanbabu was a frail, ailing old man. How could he move the stone and enter the treasury? Ishanbabu’s conscience was tainted, his character corroded by want. He did not inform Ramkishore, but began searching for an accomplice.

"Two grown men visited him daily—Ramapati and Manilal. Ishanbabu chose Manilal. The reason: Manilal was the stronger brute. And Ishanbabu had sensed that he harbored resentment against the brothers-in-law.

"Perhaps they had agreed to split the spoils fifty-fifty. But Manilal, in his heart, resolved to take it all—why should his father-in-law’s treasure fall into another’s hands? On the appointed night, the two of them shifted the stone and descended into the treasury.

"Before they could search the earthen pots, Ishanbabu spotted a gold coin on the floor. Manilal assumed the pots were filled with coins. He didn’t hesitate; with the torch in his hand, he struck Ishanbabu hard on the neck. Ishanbabu collapsed, unconscious. After that, it was no trouble to jab the pen into his foot.

"But a murderer’s mind is always in haste. Manilal dragged Ishanbabu’s body upstairs. At this moment, I suspect, some disturbance arose from outside. Murlidhar had been trying to scare Ishanbabu away—perhaps he hurled stones or bricks at that very moment. Frightened, Manilal shut the secret door. The pots went unexamined; the torch remained in the treasury.

"I doubt Manilal ever learned that there was no gold or jewels in the treasury. Before the commotion over Ishanbabu’s death had even subsided, we arrived; he had no chance to investigate further. But patience was not lacking in him; he waited, and meanwhile, flattered his father-in-law so that the fort would fall to Tulsi’s share.

"From the very beginning, he suspected that we had not come merely for a change of air, but there was nothing he could do. Then, from yesterday afternoon, a series of incidents occurred that frightened Manilal. Tulsi tried to steal his pen and give it to Ramapati. Whether the pen was poisoned at that time is uncertain, but his obsession with the pen was natural. He could not bear the sight of Ramapati—who can tolerate his beloved’s suitor? Using this pretext, he drove Ramapati away. So far, no great harm was done, but in the evening, another incident