CNN  — 

An air raid siren wails in a smoky London basement as cryptologists in military uniform are hard at work cracking codes. It could easily be a scene from World War II, except everyone’s slinging back cocktails.

This is The Bletchley, a subterranean bar on the fringes of London’s upscale Chelsea district that’s been styled to resemble Britain’s wartime code-breaking headquarters – a world of Bakelite telephones, mind-boggling equations scrawled on chalkboards, and stiff upper lips.

The real Bletchley Park – portrayed in the 2015 movie “The Imitation Game,” starring Benedict Cumberbatch – tasked prototype computers and the country’s top analytical brains with cracking the Enigma code used by Nazi Germany.

Its namesake has a different mission: To perfect a blueprint for the bars and restaurants of the future.

Suzanne Plunkett/CNN
The Bletchley -- Pop-up bar The Bletchley, located in a basement in west London's Chelsea district, is styled after Britain's World War II code-breaking HQ Bletchley Park.
Suzanne Plunkett/CNN
Role play -- Guests at The Bletchley play the part of agents. They're encouraged to wear vintage military uniform while they solve puzzles.
Suzanne Plunkett/CNN
Decoding the drinks -- The puzzles help bartenders discover the taste preferences of each customer, allowing them to mix personalized drinks.
Barry Neild
Cocktail recipes -- "Agents" are served drinks accompanied by a list of the ingredients involved. Bletchley's creator Seb Lyall says customers are rarely disappointed, but they'll get a different cocktail if they're not happy.
Courtesy Bunyadi
Bunyadi restaurant -- Lyall's previous London venture was a naked restaurant, where guests disrobed while being served food by scantily clad waitstaff.
Courtesy Bunyadi
Tech-free tables -- While The Bletchley is designed partly with Instagram in mind, Bunyadi was a tech-free environment, allowing customers to detach from their devices for a few hours.
Courtesy Bunyadi
Naked food -- The Bunyadi, which Lyall says may return in a permanent venue, served "naked" food, with raw ingredients. Thousands of people signed up to a waiting list for places at the restaurant during its three-month run.
Lollipop
ABQ bar -- Lyall's other recent venture is the ABQ bar, inspired by TV show "Breaking Bad." The bar is styled as a meth lab in a recreational vehicle parked in east London.
Lollipop
Molecular mixology -- At ABQ, guests dress in hazmat suits to mix "molecular" cocktails infused with ingredients such as dry ice.
Lollipop
ABQ on the move -- Lyall says his ABQ concept has proven so successful, he's taking it to Paris and New York later in 2017.

Bletchley is the brainchild of entrepreneur Seb Lyall. His company, Lollipop, specializes in unusual pop-up ventures such as ABQ, a cocktail bar inspired by “Breaking Bad,” and Bunyadi, billed as London’s first naked restaurant.

The new bar is designed as an immersive experience. Customers are greeted as “agents” by actors role-playing military personnel. By solving puzzles with Enigma code machines, they unlock the formulas to cocktails created specially for them.

While The Bletchley’s wartime England might seem a long way from an Albuquerque mobile meth lab and a place where folks get nude to eat, all three venues were created by Lyall using the same apparently lucrative business model.

Lyall says his company only throws opens the door to its venues once it’s sold enough pre-bookings to justify taking out a rental lease. He says has a community of 150,000 loyal followers who sign up knowing they’ll get more for their money than just food or drinks.

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Courtesy Bunyadi
Bunyadi naked restaurant: Clothes-free cuisine.

“The definition of luxury is changing for younger people,” Lyall tells CNN. “It’s not about the best cocktail or dish, it’s about experience.”

At his Bunyadi restaurant, which attracted a 46,000-strong waiting list for its three-month run in the summer of 2016, that experience was the opportunity to disrobe in candlelight and be served a three-course meal by semi-naked staff. At ABQ, still operating in a funkily decorated RV in East London and soon to open in New York, it’s dressing in hazmat suits to “cook” cocktails.

The Bletchley concept – retailing at about $37 per person – seems equally popular, tapping into Londoners’ apparently evergreen fascination with their wartime past, their passion for problem solving and their thirst for reasonably priced booze.

A lack of menus at the new bar is all part of the Lyall masterplan, forcing customers outside their comfort zone and encouraging them to engage in the role play that results in being served two bespoke drinks, in addition to the welcome cocktail they receive at the door.

“The factor of a shock is very important,” Lyall adds. “We’re bored, especially our younger generation. We’re overloaded with information on our social media platforms and we don’t really know what we like and don’t like.”

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Lollipop
ABQ bar: Cocktails + "Breaking Bad" = chemistry.

Lyall compares his business model to the increasing reliance by young people on rental accommodation in cities where they’ve largely been priced out of home ownership.

“Traditional hospitality is very different,” he says. “You buy a lease on a place and before you know you’ve spent a million pounds, and you’ll spend the next five years getting that back.

“We, on the other hand, because we’ve got a big community that follows us, we’ve got enough interest before the product is launched and we’ve broken even before we’ve opened the doors. And that gives us the flexibility to test.”

Will it catch on? Hamish Smith, deputy editor of Drinks International magazine, says such temporary concept bars meet a demand and fit the economics of a wealthy city like London.

“Pop ups are indeed the future – but only part of it,” he says. “They are fun, appealingly finite and give young experience-seeking consumers the hit of something new every time they spring up.”

Long-term though, Smith – whose magazine compiles the annual World’s 50 Best Bars list – insists there’s no threat to established luxury players from what he calls “inferior forms of the art.”

“In terms of the elite end of the business, a pop-up doesn’t cut the mustard. World-class bars are not just about cool design and theme-led concepts.”

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He adds: “Those bars with committed teams and a few years under their belt may not always be flavour of the month among the hipsters but they are built to last.”

At The Bletchley, on a fully-booked midweek night in early spring, those experience-seeking consumers certainly seem to be enjoying their hit of something new.

“It’s great, very creative,” says Michelle Finnegan, a London-based accountant visiting the bar with two fellow French Canadians. “The puzzles force you to be very random.”

Andy Barwood, on a date with wife Jane, loved it too. “Just great fun. We were struggling to decode the puzzles, and when we did, we got unusual drinks. But then we realized they were really good.”

Katie Trump, an actress and host who works at the bar as “Agent Six,” briefing customers on their code-breaking missions in the clipped upper class English tones of a wartime military officer, says even nervous guests soon warm to the immersive experience.

“You can sense those who are shy to the interaction,” she says. “You give them some cheekiness and a twinkle and they’re in.”