The Border Security Force soldiers are unfailingly polite and hospitable, but conspicuously armed and resolute. We go no further.
''Why do you need to go to the border? There is nothing there,'' we are told over endless cups of chai with progressively more senior officers, all of whom refuse us permission to travel beyond their cantonment, or photograph ''the fence'' a few hundred metres away.
The border these men patrol is not India's antagonistic front with Pakistan, nor its contested line with China.
This is India's quiet boundary with Bangladesh, a frontier that doesn't attract the attention of its querulous colleagues, but one that, in recent times, is proving equally fractious.
The fence they are so reticent to reveal is a rampart known in these parts as the ''Berlin Wall of Asia''.
Over 25 years, India has been building, and reinforcing, a massive fence along its 4053-kilometre border with Bangladesh, each renovation pushing the barrier higher, an ever-escalating posture of aggression. It is due to be finished this year.
Along this section of the border, in the northern Cooch Behar region of the Indian state of West Bengal, even the ''low'' part of the fence is four metres and floodlit, with menacing spools of razor at its base and top.
Every few hundred metres, a pair of armed Border Security Force soldiers stand guard in a small watch-post, scanning the fence with binoculars.
The fence along here will be reinforced soon, replaced by an even more intimidating barrier.
But more than the simple fact of building a border fence, at issue has been India's manner of policing it.
''India and Bangladesh are friendly countries, they are not enemies,'' Kirity Roy, the secretary of the Indian human rights group Mausam, tells the Herald.
''But the Indian government's paramilitary organisation, the Border Security Force, they are … trigger happy, they are killing Indians and Bangladeshis without discrimination. And they are killing with impunity because they are never charged or given any punishment.
''The BSF should protect the border and stop people crossing illegally, but they cannot torture or injure or kill people. That is not their job.''
Across the border, Mausam's sister organisation Odhikar has documented nearly 1000 cases of Bangladeshi nationals shot and killed trying to cross this line since 2000.
Last year, the BSF shot and killed 31 people, injured 61 and abducted 23, Odhikar says.
''In flagrant violations of international norms and treaties, Indian Border Security Forces shoot and kill unarmed Bangladeshi civilians in the border areas and, on occasion, even inside Bangladeshi territories.''
A Human Rights Watch investigation found killings on both sides of the fence, as well as beatings, torture, kidnappings and rampant corruption.
''The abusive methods used by the BSF are disproportionate to the problems that the Indian government faces on its eastern border. Numerous ordinary Indian and Bangladeshi citizens resident in the border area end up as victims of abuses, which range from verbal abuse and intimidation to torture, beatings and killings.
''Even the most serious abuses by border guards go unpunished. This sends a clear message that the Indian government finds such abuses acceptable.''
Under growing pressure to stem the tide of deaths along the border, the BSF last year promised to introduce non-lethal weapons for soldiers on the fence. But the Herald sees none during our time along the border. The first option, the only option it appears, remains to reach for the rifle.
In January the BSF director, Utthan K. Bansal, said soldiers should exercise restraint, but warned they would shoot if they felt threatened.
''If … they get into a situation where they are threatened and their life is in danger, they will use the force available with them to save their lives or the lives of their companions. That means they will fire.'' He said soldiers would use whatever weapon was available.
''Even that firing he will do as far as possible with an intent not to kill but, if the casualty occurs … we will have to tolerate it as an inescapable alternative.''
As if to belie the director's emphasis on restraint, just days later a brutal video was posted on YouTube showing uniformed BSF soldiers stripping naked a suspected Bangladeshi cattle smuggler, tying his arms to a pole and beating him with bamboo sticks for more than 10 minutes as he writhed on the ground and screamed for his mother.
India's border fence - and its vehement defence of it - exists for all manner of reasons, real and imagined.
India sees this imposing barrier as a panacea against the evils it believes lurk across the border, from the very real problem of people smuggling, to the less-likely threat of Islamist terrorists, to the speculative future problem of a millions-strong refugee tide coming from Bangladesh.
Black-market commerce thrives in this part of the world.
Cows are smuggled from Hindu India into Muslim Bangladesh, where they can be slaughtered, while textiles and mobile phones, cheaper in Bangladesh, are brought the other way.
The smuggling of people, particularly young women, is common too.
But the fence's fundamental purpose is far simpler: to keep out Bangladeshis. The xenophobe card plays strongly in Indian politics, and senior officials, like the Home Minister, P. Chidambaram, have lost no support lecturing that Bangladeshis ''have no business to come to India''.
Already the Indian government believes it is burdened by between 10 million and 20 million illegal economic migrants from Bangladesh.
It fears millions more Bengalis will flood over the border if their country's economy continues to founder, and those numbers will multiply if the projected impact of climate change leaves tens of millions in low-lying Bangladesh homeless or foodless, displaced by disaster or without arable land to sustain them.
Yet, for all the cost of building the fence - upwards of a billion dollars so far - and the violence along it, both sides of the border know it is no border at all.
Dozens of villages act as unofficial, illegal transit posts. At each, a ''lineman'', handsomely remunerated, pays off the guards from both notoriously corrupt countries, and directs the illegal traffic, which can run into scores of people at a time, across the border.
But Suman Islam won't go back there: ''I fear the same as they have done to me in past. If I again meet them, they will do it again.'' We meet Suman at a friend's home 10 kilometres from the fence line, safely in Indian territory.
His family own land on the border and into no-man's land between the two fence lines, where they grow wheat and jute.
In December last year, Suman says, he was walking just after dark near the Indian side of the border.
''My family has a house there, and I go there often, it was not unusual. Suddenly, they flashed a torch on me and then they shot.'' Suman survived, dragged to hospital by family who heard the firing. But he has been left with dozens of pellets lodged in his chest and face. He has lost all sight in his right eye.
Yet he considers himself lucky. Others do not survive, others like 15-year-old Felani Khatun who was trying to cross into Bangladesh to be married. She was shot when her salwar kameez became caught in the wire. Her screams alerted the guards, who shot her as she struggled.
Her body was left hanging on the fence for five hours before it was cut down.
''I hear all the stories and I have seen with my own eyes,'' Suman says. ''They [the BSF] rule over the border. Whatever they say goes. If they say nobody can walk on the road, then nobody can walk there.''
The fence they are so reticent to reveal is a rampart known in these parts as the ''Berlin Wall of Asia''.
Over 25 years, India has been building, and reinforcing, a massive fence along its 4053-kilometre border with Bangladesh, each renovation pushing the barrier higher, an ever-escalating posture of aggression. It is due to be finished this year.
Every few hundred metres, a pair of armed Border Security Force soldiers stand guard in a small watch-post, scanning the fence with binoculars.
The fence along here will be reinforced soon, replaced by an even more intimidating barrier.
But more than the simple fact of building a border fence, at issue has been India's manner of policing it.
''India and Bangladesh are friendly countries, they are not enemies,'' Kirity Roy, the secretary of the Indian human rights group Mausam, tells the Herald.
''But the Indian government's paramilitary organisation, the Border Security Force, they are … trigger happy, they are killing Indians and Bangladeshis without discrimination. And they are killing with impunity because they are never charged or given any punishment.
''The BSF should protect the border and stop people crossing illegally, but they cannot torture or injure or kill people. That is not their job.''
Across the border, Mausam's sister organisation Odhikar has documented nearly 1000 cases of Bangladeshi nationals shot and killed trying to cross this line since 2000.
Last year, the BSF shot and killed 31 people, injured 61 and abducted 23, Odhikar says.
''In flagrant violations of international norms and treaties, Indian Border Security Forces shoot and kill unarmed Bangladeshi civilians in the border areas and, on occasion, even inside Bangladeshi territories.''
A Human Rights Watch investigation found killings on both sides of the fence, as well as beatings, torture, kidnappings and rampant corruption.
''The abusive methods used by the BSF are disproportionate to the problems that the Indian government faces on its eastern border. Numerous ordinary Indian and Bangladeshi citizens resident in the border area end up as victims of abuses, which range from verbal abuse and intimidation to torture, beatings and killings.
''Even the most serious abuses by border guards go unpunished. This sends a clear message that the Indian government finds such abuses acceptable.''
Under growing pressure to stem the tide of deaths along the border, the BSF last year promised to introduce non-lethal weapons for soldiers on the fence. But the Herald sees none during our time along the border. The first option, the only option it appears, remains to reach for the rifle.
In January the BSF director, Utthan K. Bansal, said soldiers should exercise restraint, but warned they would shoot if they felt threatened.
''If … they get into a situation where they are threatened and their life is in danger, they will use the force available with them to save their lives or the lives of their companions. That means they will fire.'' He said soldiers would use whatever weapon was available.
''Even that firing he will do as far as possible with an intent not to kill but, if the casualty occurs … we will have to tolerate it as an inescapable alternative.''
As if to belie the director's emphasis on restraint, just days later a brutal video was posted on YouTube showing uniformed BSF soldiers stripping naked a suspected Bangladeshi cattle smuggler, tying his arms to a pole and beating him with bamboo sticks for more than 10 minutes as he writhed on the ground and screamed for his mother.
India's border fence - and its vehement defence of it - exists for all manner of reasons, real and imagined.
India sees this imposing barrier as a panacea against the evils it believes lurk across the border, from the very real problem of people smuggling, to the less-likely threat of Islamist terrorists, to the speculative future problem of a millions-strong refugee tide coming from Bangladesh.
Black-market commerce thrives in this part of the world.
Cows are smuggled from Hindu India into Muslim Bangladesh, where they can be slaughtered, while textiles and mobile phones, cheaper in Bangladesh, are brought the other way.
The smuggling of people, particularly young women, is common too.
But the fence's fundamental purpose is far simpler: to keep out Bangladeshis. The xenophobe card plays strongly in Indian politics, and senior officials, like the Home Minister, P. Chidambaram, have lost no support lecturing that Bangladeshis ''have no business to come to India''.
Already the Indian government believes it is burdened by between 10 million and 20 million illegal economic migrants from Bangladesh.
It fears millions more Bengalis will flood over the border if their country's economy continues to founder, and those numbers will multiply if the projected impact of climate change leaves tens of millions in low-lying Bangladesh homeless or foodless, displaced by disaster or without arable land to sustain them.
Yet, for all the cost of building the fence - upwards of a billion dollars so far - and the violence along it, both sides of the border know it is no border at all.
Dozens of villages act as unofficial, illegal transit posts. At each, a ''lineman'', handsomely remunerated, pays off the guards from both notoriously corrupt countries, and directs the illegal traffic, which can run into scores of people at a time, across the border.
But Suman Islam won't go back there: ''I fear the same as they have done to me in past. If I again meet them, they will do it again.'' We meet Suman at a friend's home 10 kilometres from the fence line, safely in Indian territory.
His family own land on the border and into no-man's land between the two fence lines, where they grow wheat and jute.
In December last year, Suman says, he was walking just after dark near the Indian side of the border.
''My family has a house there, and I go there often, it was not unusual. Suddenly, they flashed a torch on me and then they shot.'' Suman survived, dragged to hospital by family who heard the firing. But he has been left with dozens of pellets lodged in his chest and face. He has lost all sight in his right eye.
Yet he considers himself lucky. Others do not survive, others like 15-year-old Felani Khatun who was trying to cross into Bangladesh to be married. She was shot when her salwar kameez became caught in the wire. Her screams alerted the guards, who shot her as she struggled.
Her body was left hanging on the fence for five hours before it was cut down.
''I hear all the stories and I have seen with my own eyes,'' Suman says. ''They [the BSF] rule over the border. Whatever they say goes. If they say nobody can walk on the road, then nobody can walk there.''
