In 1947, as a birthday present for Queen Mary, Agatha Christie wrote a radio play called Three Blind Mice, about eight people snowed in, in a manor—one of them (who, we don’t know till the end) a murderer. Later adapted into a short story and then a theatrical play called The Mousetrap (because Three Blind Mice was already the title of a play), Christie’s work set a record. The Mousetrap, which saw its 30,000th performance in March 2026, is the longest-running play in history.

Such an iconic play, such a popular one, surely it must have been adapted for the screen many times (especially given the popularity of Christie’s books as source material for cinema)? But no; when the play was first staged at West End, one of the clauses in the contract was that no work on a cinematic adaptation could begin until the West End production had been closed for at least six months. And the play continues to be performed at West End…

But that, it seems, didn’t stop film-makers in other countries from using the story and making their own versions of it. The Bengali film Chupi Chupi Aashey (‘He Comes Stealthily‘) is an adaptation of The Mousetrap, and was supposedly the first Indian film to be based on a book by Agatha Christie.

Directed by Premendra Mitra, the story begins on a damp night in Kolkata. A man, wearing a raincoat and a cap pulled low on his head, knocks at a house in Girimaji Lane. The maid (Asha Debi) who opens the door directs him to an upstairs room—where a Mokhada Devi, whom the man has asked for, lives. The maid goes out the front door, yelling out to Mokhada Devi that she’s leaving for the day.

And Mokhada Devi (Namita Debi) stares in shock at her unexpected visitor…

The next day, at the local police station, the police inspector and his assistant are discussing a murder: Mokhada Devi of Girimaji Lane was killed in her home last night, by an unknown assailant. They are talking about the lack of clues when two men arrive at the station, bringing a clue.

These two are workmen and had been working at Girimaji Lane the previous night. The older of the two men needed a match to light his beedi, and seeing a raincoat-clad man walking down the street, had asked him for one. The man has handed over the entire matchbox and gone his way, not realizing that in taking it out of his pocket, something else had also fallen out.

A flyer, advertising a Kalyaneshwari Health Resort. This the beedi-smoker had picked up and wrapped round the matchbox, both of which he now hands over to the inspector. In addition to the matchbox and the flyer, the workmen share another detail about the murderer: he was whistling a tune, a very popular film song, the words of which go Chupi chupi aashey.

The men gone, the cops examine the flyer of Kalyaneshwari Health Resort; the assistant is inclined to dismiss it as being of no importance, but the inspector notices that on the reverse side of the flyer is written, in pencil, that ‘this began at Girimaji Lane, and it will end at Kalyaneshwari’ or words to that effect. The inspector immediately phones someone (a senior officer? It’s not clear?) named Mr Dey.

… but before the conversation happens, the scene has shifted to a Marwari shopkeeper’s store, somewhere outside Kolkata. Chupi-chupi aashey is playing really loud on the radio, while two people—Prabir Lahiri (Robin Majumdar) and Kanika (Tapati Ghosh)—are ordering supplies.

Prabir and Kanika are good friends and partners in a venture: they run the Kalyaneshwari Health Resort. Right now, they’re busy stocking up, because it’s been pouring cats and dogs and there’s a very real possibility that their ‘health resort’ (why they call it that when it’s really nothing more than a guest house, is beyond me) is in danger of getting cut off.

Later that evening, Prabir and Kanika are frantically rushing about, trying to get things in order. There are a couple of servants to help out, but they need to leave for their homes before the rain floods the area around. Besides, various guests have begun to arrive. These are mostly people who have booked rooms beforehand:

A Miss Dhar (Sushama Ghoshal), for one, who finds fault with everything she is faced with. Nothing is to her liking, and all through the evening and the following day, she complains about every single thing in her room, at the resort, around and about.

Then, there’s a man (Prabir Kumar) who comes striding along, dressed in a raincoat and looking uncannily like the murderer we had last glimpsed in Girimaji Lane. This man calls himself Madhusudan Dutt and is a garrulous, irreverent sort, the exact opposite of the snooty and hard-to-please Miss Dhar.

There is already a somewhat cagey-looking man named Dr Bajpai (Samar?) in residence, but for now, at least, we learn nothing more about him. Instead, two other visitors arrive. One of them, a non-Bengali named Radheshyam Veeraswami (Jahar Ganguly; I’m guessing he’s supposed to be from Tamil Nadu), was not actually booked here. His car broke down nearby, and searching for a place to take shelter, he’s washed up (quite literally) at the Kalyaneshwari Health Resort.

The man with whom Veeraswami arrives is an elderly, frail person, Mr Beni Prasad (Chhabi Biswas). Beni Babu is so infirm that he has to be pretty much helped to his room.

Even before nightfall, things have started hotting up at Kalyaneshwari. Miss Dhar comes to Kanika, complaining of weird sounds in her room (to which Kanika simply replies that in a storm such as the one they’re in the midst of, such sounds are normal). Miss Dhar is unconvinced; she is certain there are ghosts around.

Then, a telephone call comes: a Mr Dey is calling from the police station to say that a CID officer, an Inspector Ghoshal, will be arriving at the health resort. Prabir tries to dissuade Mr Dey, pointing out that their health resort has now become like an island, water for miles around. Inspector Ghoshal will not be able to come. But Mr Dey hangs up without listening.

Kanika is pretty distressed at the idea of a CID officer coming to the place: why? What is the matter? Are they suspected of some crime? Prabir calms her down, but it’s obvious that Kanika is very worried.

By the next morning, the news of the CID officer’s imminent arrival has spread, and Veeraswami and Dr Bajpai, who learn of it, are equally puzzled (in Bajpai’s case) and distressed (in Veeraswami’s). They are still wondering why, and—importantly—how he will get to the resort, but Ghoshal (Tarun Kumar Chatterjee) comes on a raft, poling himself along till he reaches the front door of the resort.

Shortly after Ghoshal arrives, Dr Bajpai—who’s been trying to make a phone call—remarks that the phone has gone dead. Kanika checks, and sure enough. How odd.

Ghoshal sits down with Prabir and Kanika and gives them the background, explains why he’s come. Did they know Mokhada Devi, who was murdered in Girimaji Lane? No? Then do they perhaps know of the Chapa Khola Orphanage case? They don’t, so Ghoshal tells them. Years ago, Mokhada Devi’s husband was the manager of the orphanage, where many children whose parents had died in communal riots were housed. The manager and his wife used to treat the children really badly, and eventually three siblings tried to escape.

They didn’t make it; they were caught and beaten so brutally that the youngest child died. Mokhada Devi and her husband were arrested, but he died a few days later in a car accident. The case was closed; Mokhada Devi left Chapa Khola and went and settled in Girimaji Lane. Ghoshal’s idea is that one of the two remaining children—the siblings of the child who died at the hands of Mokhada Devi and her husband—now grown up, is seeking revenge. He (or she?) has already murdered Mokhada Devi, and is now headed for Kalyaneshwari Health Resort—Ghoshal mentions the message scribbled on the back of the flyer—to kill yet another person.

Prabir and Kanika point out that nobody can come to the resort now; they’re surrounded by water, completely isolated. But Ghoshal offers a chilling counter to that: there is no need for anybody to come. The murderer might already be here, among them. One of these boarders may be the person who killed Mokhada Devi, and who has come here to Kalyaneshwari to murder someone else.

Who is the murderer? And who will be the next victim? Several of the people within the house act in a fairly suspicious way. Madhusudan, for instance, who (though he’s so carefree, even flippant), is obviously using a false name (why?). Why does Dr Bajpai prowl around the place, looking out every now and then? Why did Prabir go on the sly to Kolkata, deliberately hiding it from Kanika?

And is there really a ghost at Kalyaneshwari, making spooky noises and appearing as a tall, dark shadow that flits about the corridors?

Comparisons, what I liked, what I didn’t:

There are obvious changes in the story, perhaps to make it more suitable for an Indian audience. In The Mousetrap, the two people who own and run the guest house are a married couple, though they’ve been married only a year (did Premendra Mitra think a romance between people married to each other wouldn’t work?). The setting is a guest house, not a health resort (given that Kalyaneshwari doesn’t appear to have any facilities that might allow it to qualify as a ‘health resort’, I wonder why this change was made). There is no equivalent of Dr Bajpai in the original play, and the character played by Chhabi Biswas mirrors a very different character in the play.

But despite the differences in the details, Chupi Chupi Aashey is very obviously an adaptation of The Mousetrap, and a fairly good one at that. As an adaptation goes. Because, for me, the original play has some flaws too, one being that the conversations between various characters tend to be a bit confusing at times, to the extent that people seem to be suspicious of each other one moment, and then the suspicion seems to dissolve for no good reason—and vice-versa. This was one of the elements of Chupi Chupi Aashey that I didn’t like: too many conversations that didn’t go anywhere, just skirted around suspicion and then fizzled out. In the middle, it began to drag a bit, and I found my attention wandering.

Then, the ghost angle. Why was that made so much of? When a story centres round a murder mystery, and there’s such a powerful angle to it—a murderer, one of just a handful of people in the house, and looking for the next victim—why bung in a supernatural angle to it as well?

All said and done, not an absolutely flawless film. It could have been better. But it’s still a fairly entertaining film; the title song (sung by Sandhya Mukherjee) is good, and Chhabi Biswas’s acting is—no surprise, this—superb.

If you want to watch Chupi Chupi Aashey, there’s a version here, with English subtitles.