[Dr. Emily Zarka] Imagine a calling to you from the darkness, the voice of someone you loved who recently died.

You're terrified, but you can't ignore the hypnotic promise of seeing them again.

You venture outside to find the source, a fatal mistake.

This is the lure of the Nishi.

Hailing from Bengali folk tradition, these cruel monsters are also known as Nishi Daak, which roughly translates to call of the darkness or the call of the night.

The lines between demon spirit and deity are often blurred in cultures of the Indian subcontinent.

The clear good-versus-evil dualism seen more commonly in the western hemisphere doesn't exist in the same way.

The Nishi falls firmly into the malevolent end of ghostly beings and teaches us a lot about the culture it comes from.

[rousing music] I'm Dr. Emily Zarka, and this is "Monstrum."

The Nishi Daak is one of many bhoots, or ghosts, in Bengali tradition.

There are so many types of ghost stories in Bengal.

By Bengal, I mean the country of Bangladesh as well as West Bengal in India, the state.

We used to all be one big region.

Of course, after the partition of India in 1947 when we achieved our independence, we became two separate countries.

But our stories and our fo lklore traverse those borders of both nationality, religion, class, and the like.

That's Dr. Sayantani DasGupta, assistant professor at Columbia University and children's and YA author.

[DasGupta] But the Nishi is a slightly different malevolent entity than the rest of Bengali ghost lore.

Tales of these harmful night spirits are prevalent in small and rural villages.

They pose a deadly threat to those who wander at night.

Nishi call out to peaceful sleepers in a familiar voice, usually a deceased loved one.

One story I've heard about the Nishi is that they are a kind of disembodied, ghostly form that can call you, mimicking the voice of a loved one.

So, for instance, if at night, walking by a deserted bamboo forest, you were to hear somebody calling your name, somebody very familiar, for instance, an aunt or a beloved cousin calling you maybe even in a nickname that only they know, don't turn around because it may be a Nishi trying to trick you out of your spirit.

While the monster adopts the voice of someone their victim knows, these malevolent spirits aren't necessarily the ghost of the person's voice they are adopting.

The complex nature of Nishi is reflective of the spiritual community from which these monsters originate.

The very idea of a ghost becomes additionally complex in cultures where spiritual practices center around the ideas of reincarnation, ancestral worship, and karma, like Hinduism.

In Hinduism, the subtle body or second body is the part of a person that is reincarnated into another physical form.

The deceased corporeal form must be completely obliterated so the subtle body can move on, hence the preference for cremation.

This also means Bengali ghosts don't have gravesites to haunt.

Bengalis, and particularly Hindu Bengalis, have the notion of rebirth and reincarnation, and so Bengali ghosts are sometimes perceived of as recently deceased people who have not been able to enter th e cycle of reincarnation.

But sometimes Bengali ghosts are actually thought of as creatures, monsters of their own kind, a kind of different species in and of themselves.

Now, Nishi or Nishi Daak are not exactly among this category of spirit because they exist in a far more sinister and disembodied form, unlike a lot of other Bengali ghosts.

An exclusively malevolent spirit like a Nishi can be the result of incomplete or improper funerary rites.

The deceased fails to transition their subtle body and thus cannot be reincarnated.

And since no one wants more Nishi, protecting and executing cultural burial rights is paramount.

If we see the call of a Nishi as a way the spiritual body continues to link itself to the physical body, the corporeality of the voice becomes particularly interesting.

What if a Nishi cannot be heard?

Does it cease to exist?

Or does it become even more ambiguous and ominous?

The fact that the Nishi can steal or mimic the voice of a deceased loved one seems particularly threatening in this sense.

It suggests we cannot fully trust the dead or our own ears in such a way that it will cause our demise, which, quite frankly, is pretty terrifying.

Yet the call of the Nishi is hard to ignore.

Only the chosen victim can hear th e Nishi's hypnotic voice.

Interestingly, these beings cannot call out to you more than two times, so superstition dictates that you never respond to anyone ca lling your name at night unless you hear it three times.

Those who do fall under the influence of a Nishi fall into a trance and will follow the distant voices to a remote area.

And these nighttime strolls are dangerous.

If one is unable to break the Nishi's influence, they disappear, presumably killed.

While the Nishi can call to or even grab their victims, visual details of the monster tend to be vague.

In some accounts, the Nishi appears as a shadowy or indistinct form resembling the person's voice they mimic.

In others, they are an all-white, misty entity with a vaguely human shape.

The ambiguity highlights its mutability and lets the imagination run wild.

In one story translated by Dr. Suchitra Samanta, a Nishi directs its attention to a little boy.

The boy shared a close bond with his aunt who helped raise him.

He would lovingly catch his aunt's favorite freshwater fish to eat.

When she died suddenly, the boy was too devastated by grief to perform his aunt's last rites.

He would not eat or speak, becoming ill himself.

Exorcists were brought in, amulets and charms applied, but nothing worked.

One night, the boy woke suddenly, claiming he heard his aunt's voice calling to him.

Soon rumors spread of a figure sitting in a tree at a nearby pond.

Then after a heavy monsoon rain, a midnight fog encased the village.

The boy again hears his aunt calling to him, begging him to come catch her fish.

So he sneaks out of the house and begins to collect the fish, but then he spots a figure in the trees.

Fear brings the boy back to his senses, and with much effort he is able to run.

But he doesn't get far before a long arm snatches his basket of fish, and the boy falls into a dead faint.

Three days pass before he regains consciousness.

Everyone warns his mother to keep a close eye on the boy, for next time, he might have his neck broken by the Nishi.

But the monster is relentless and lures the boy into the pond.

He walks straight in, sinking below the surface.

His body is dragged up in the fisherman's nets the next morning.

Elements in this story give insight into some cultural practices and taboos.

It isn't farfetched that the boy's affliction was treated with a variety of methods, including exorcism.

Belief in spirit possession and malicious sorcery is common in this region even today, although controversial.

Some religious sites are known for exorcisms but face increased scrutiny in the modern day.

An afflicted person might make a pilgrimage to one of these temples or shrines to remove any negative spiritual or supernatural ailment.

Policy reforms and growing awareness of mental health challenges have made these temples and shrines divisive, arguing that they encourage superstition and can do more harm.

But others counter that they offer a form of traditional alternative healing that should not be dismissed or demonized.

Like many other night spirit stories, the victim wanders off and dies at night.

Because of this, Nishi influence is often said to be responsible for a particular trance-like state, sleepwalking.

Fun fact, I used to sleepwalk as a kid.

One night, my parents found me knee deep in our pool, something I have zero memory of.

Death by sleepwalking is rare, but injuries aren't uncommon.

Perhaps the Nishi serves as an explanation for this strange phenomenon and helps the community stay alert and keep sleepwalkers safe.

Nishi Daak stories are also told to make sense of horrible illnesses.

So let's say there's a child who, for no explainable reason, without any treatment, is getting sicker, kind of wasting away in a family.

You might say that the Nishi has called away their life force.

So the notion is that maybe somewhere else in the village or somewhere in the locality, a wealthy family with an ill child of their own has employed a tantric or a magician of some sort to wander around the neighborhood saying a particular magical mantra and carrying around a hollowed-out green coconut in which they hope to trap the essence, the soul, or the life force of a healthy young person and give it to this ill one.

So in a community with high rates of infant mortality and childhood illness, stories like those of the Nishi Daak may have been a way for families to make sense of what was completely un-understandable and happening before their eyes.

[Zarka] Let's go back to the creepiest part of this monster and the thing that literally defines it, the disembodied voice in the night.

People have been trying to understand the phenomena of the disembodied voice for quite some time.

From exploring the validity of religious communications to assessing clairvoyance, even now, we look for answers in both the secular and the scientific.

As technology and urbanization continue to evolve and literally bring light to the darkness, so do the stories of the Nishi, but that doesn't make them any less important.

As a Bengali immigrant daughter to the US, Bengali folk stories, stories about flying horses, princes and princesses, evil serpent kings, and even monsters like the carnivorous, drooling rakkhosh and of course the ever-present Bengali bhoot were literally what connected me to my cultural roots.

These were stories that were told to me by not only my parents but my grandparents.

Oral stories are critical to communities throughout the world.

And I think particularly to diasporic communities who are raising children far from their homeland, folk stories, monster stories, ghost stories are a way to connect young people to their origins, to their ancestors, and to their sources of cultural belief.

These stories are deliciously frightening sometimes to listen to, but they're also deeply meaningful.

Somewhat ironically, given the Nishi Daak's dangerous call, in speaking and hearing their stories, we preserve their importance.

The deceased corporeal... Community stay alert and keep safewalkers safe.

Oh my God, I started it and couldn't stop myself.

Nishi Daaks, Daaks.