But the network was patchy and his video kept freezing, even though the family could hear him. At one point, Manica said, there was a sudden jerk “as if he had bent over to pick something up”, and the call got disconnected.

That is the last time the family heard from Agarwal.

Since that phone call and the abrupt disconnection, Agarwal has been missing – disappeared, without a trace.

Agarwal’s case is far from unique.

Over the years, dozens of tourists like Agarwal, many of them foreign nationals, have gone missing while visiting the Parvati Valley in the state of Himachal Pradesh.

Often, they seemingly vanish, earning the valley monikers like “India’s Bermuda Triangle” and “Death Valley”.

Official figures are hard to come by, but according to Indian media reports at least 21 foreigners have gone missing from here in the past three decades. Locals say the real number is much higher. The last high-profile disappearance that made the news was in 2016, when American tourist Justin Alexander disappeared while on a trek down from the Mantalai lake.

Parvati Valley’s streets are testament to this. The walls of government buildings, electricity poles, public toilets; all are filled with posters of people who have gone missing in the area.

Breathtaking beauty, dark secrets

What makes the valley so alluring to backpackers and tourists is a potent cocktail of breathtaking beauty and dark secrets.

Aditya Kant, a senior journalist and author of High on Kasol, a recent fictional book set in the Parvati Valley, said that tourists who came to the valley were “curious”.

“Almost everyone who comes here has heard of the high-quality drugs that the valley is famous for and is curious for a taste of it,” Kant said. “Adding to this are the sweeping landscapes, so picturesque that this valley is often called ‘Mini-Switzerland’.”

Nestled in the lap of the mighty Himalayas, the valley’s worst-keep secrets include being the destination for psychedelic rave parties, often fuelled by Malana Cream, a locally-grown aromatic hashish, one of the most expensive in the world.

The drug is named after Malana village, an ancient area of the valley that is shrouded in mysterious customs and self-imposed seclusion where cannabis cultivation flourishes.

“In the late 1980s, Israeli tourists started flocking here at a time when this valley seldom saw Indian tourists and the drug trade received a big boost,” Kant said. “This influx slowly made the valley a popular destinaton among foreign tourists.”

The Israeli connection to the valley remains intact and visible - restaurants have menu cards in Hebrew and some guest houses are named after Jewish mythical characters.

But it is not only thrill-seekers who come to the valley. Many visitors come in search of tranquillity and solitude, especially those who travel to the valley’s upper reaches which are inaccessible by motorised transport.

Agarwal’s brother, Abhishek, said he was one such tourist. “When he told us he wanted to go there, we wondered why he insisted on going alone,” he said. “I told him to take someone along, but he said he wanted to go alone, to find peace and solitude.”

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Legends, myths, ascetics

Still, those drawn to the valley by its spirituality have occasionally met dark ends.

In August 2016, the American traveller Alexander, who was living in Parvati Valley, decided to trek to the upper reaches of the Himalayan range, to Mantalai lake which lies at 4,000 metres. Alexander, who had been living in a cave, decided to go hiking with a Hindu ascetic, ostensibly to learn more about meditation techniques. On September 3, that year, Alexander was spotted apparently on the return leg of the trek, but he was never seen again. “He never made it,” reads an announcement on his Facebook page, posted a month later, by his friends and family.

Alexander had grown close to the ascetic, Sat Narayan Giri, and had featured him on his social media posts where he described the holy man as someone so otherworldly that he had “even cut off his penis”. Alexander seemed enamoured by the “magical powers” that ascetics like Giri were rumoured to have.

After Alexander’s disappearance, the local police arrested Giri. Just days before custody was to expire, Giri was found hanging from the bars of his police cell. Five and a half years later, there is no word on Alexander.

Tricky terrain

Adding to the murky and mysterious ways of the valley is its terrain. The valley’s upper reaches have no roads fit for motor vehicles; the only way to reach them are by trekking, often along precariously narrow pathways on tall mountain slopes with precipitous drops.

Local hiking experts are often co-opted to search for those who go missing.

“The valley can be treacherous, because the slopes get narrower as you go higher up,” said Manu Mahajan, a mountaineer who belongs to the Himalayan Rescue Mission.

Mahajan has taken part in various searches over the years. Usually, success means retrieving the remains of a person who has died.

“It is so dangerous in spots that one small mistake and you end up in the Parvati river, thousands of feet below,” he said, “and nothing that goes into the Parvati ever comes back.”

At the Manikaran police station, a nondescript ground structure manned by a handful of police stations, Agarwal’s disappearance evokes a strong sense of familiarity and foreboding – its walls are covered with posters of people who have gone missing.

The police station overlooks the expansive valley and the mountain ranges that include popular trekking destinations like Kheerganga, where Agarwal was headed.

Police officials there, not willing to be named, questioned the wisdom of Agarwal’s decision to trek to Kheerganga alone.

“His family told us that he had never trekked before,” said a police official.

“Tourists have to become responsible and have local guides and porters who can help them on such treks and not risk going alone.”

More intrigue

But the Agarwal family dismiss such suggestions and are angry at what they believe was a botched investigation.

The family has done what it could – hired a private rescue team, spent hundreds of dollars looking for their son, mounted social media campaigns, pressured the country’s high offices to use their influence.

But the police, they said, had not done enough.

“Even the CCTV footage showing Agarwal in a shop, buying winter clothes, was obtained from the shop by us and not the police,” said his sister, Manica.

Even as the family fights their disappointment, they try to keep their hopes up.

In this battle between hopelessness and hope, a series of phone calls have added to the mystery while possibly shedding light on what might have happened to Agarwal.

More than two months after Agarwal went missing, the family received calls from two Indian trekkers, calling from separate parts of the country. They said they had seen posters about Agarwal’s disappearance on social media and wanted to help.

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They had not met Agarwal, nor did they know his whereabouts, but they did have information that could help the family understand better what could have happened. They had trekked in the same area as solo travellers who had gone missing and believed they had escaped a similar fate by a whisker.

Both trekkers had come across a group of young women who sought to “lure” solo male travellers trekking in the mountains. One of the trekkers had even consumed something they gave to him, only to wake up three days later, with no memory of what happened afterwards. However, adding to the mystery, the young women had apparently not stolen anything from the trekker.

“They told us that this gang of girls are always on the prowl for solo male travellers,” Manica said.

For the family, the explanation seems plausible. After all, Agarwal was alone and a big city businessman, carrying cash and his bank cards.

“My brother was someone who had a pure heart and trusted people easily,” Manica added.

“Maybe they have done something similar with bhaiyya [my brother].”