Voltaire and Rousseau is an eclectic bookshop with a clientele to match.
Foraging amongst the endless stacks of second-hand books, plucking out motor manuals and battered hardback fiction is an array of customers; from wooly-jumpered students to eccentric, ageing academics.
Since 1972, book-collecting brothers Joe and Gerard McGonigle, with help from other siblings Eddie and Ian, have served the West End's bookworms and have garnered an overwhelming amount of literature.
With development plans for Otago Lane now granted after a three year David-and-Goliath struggle between residents and developers, the brothers are expecting a hit more damaging than the introduction of the Kindle.
Permission has been granted to build 49 dwellings directly across from the bookshop, which threatens to limit space outside the shop and disrupt the bohemian ambience of the Lane.
As two of the four brothers involved in the shop guide me around the tiny space, their concern for the future of the Lane and the people who love it is clear.
"Everyone says they feel as though they couldn't imagine the place ever not existing," says Ian, the eldest McGonigle.
"One guy that comes in has four kids, and he says that coming here is the breathing space that he has - even if he doesn't find anything, he couldn't imagine the shop not being here because he needs it."
"Sorry about the mess," he adds.
"It's normally a bit tidier than this, but it's after the weekend, you know."
I've never seen the bookshop look any different. To my memory all shelves, floor space and counters have always been scattered with books, leaving little space to tip-toe around the knee-high towers of literature that populate the carpet.
Brothers Joseph and Gerard McGonigle first opened a shop in Park Road in the 1970s before expanding into Otago Lane, back when the book business was booming.
Pre-Amazon.co.uk and downloadable fiction, the West End academics thrived between the shelves of Voltaire and Rousseau and visitors bought up books to be shipped back to their home countries.
Ian fondly remembers preparing a collection of 300 books for an American businessman, weighing them on a bathroom scale and wrapping them in paper with their ends open so they could make it easily through customs.
"In business, when someone buys a lot of stuff you take them for a meal," says Ian of the shipment.
"We took him to a pub in Argyle Street for pie and beans and a pint."
As voracious readers, the McGonigle brothers continue to amass thousands of books, buying and selling them from different places all over the country.
They clear bookcases when people's relatives pass away, buy books from auction and trade with customers who bring them in.
The brothers also rent out books to film companies, and Voltaire and Rousseau even became the set of a television show as part of Channel 4 series, The Book Group.
The dishevelled shop floor with books stacked to the rafters is only a hint at the extensive archive spilling out in storerooms above.
"What sells the fastest is Bukowski," says Eddie of the shop's most popular author and cynical novel, Post Office.
"There's lots of students round here and he's the student favourite. He talks just about how he worked for the post office and had a low-paid job, and it's all about people who can't get jobs.
"There's also a man who has been coming since the first week we opened, he still comes in. He's a bit fanatical so he doesn't ever want to speak to anyone, he thinks people will think he's only got books in his house."
As Ian and Eddie guide me around the bargain section, highlighting the fact I can get a French dictionary or an archaeology book for £1, a German girl spending her first day in Glasgow announces her love of the shop's curious collection of books.
The brothers nod and shrug, having heard it a thousand times from generations of happy customers.
"We're world famous - see the big cruise ships that come to Greenock, the big liners, they have a list of places to see and our shop's on it," says Ian proudly, squeezing through customers and wooden step ladders to show me the history section.
"Once a group came up in a taxi and they had a list of places to see, and on it was: town, Loch Lomond and here. They came here first.
"Every year, about 24 Evangelists come in and raid the theology bit. They save up, pay their own fare and board and come down to get the theology books."
It's clear that it's the idiosyncrasies of Voltaire and Rousseau, the muddle of books and rich history packed within its shelves and the passion of the men behind it that make the little shop such a beloved part of the West End.
It's not a flashy franchise bookshop-come-café that charges through the nose, nor can you easily call up a book title in a computer database and instantly know which shelf space to find.
With developers preparing to build opposite the tiny shop and its neighbouring record store, clock restorer and tearoom, the brothers are worried that the aesthetics and atmosphere of the Lane are set to change.
"They've said the development can go ahead. It won't close the shop, but if there's vast amounts of work going on it will be noisy and dusty.
"It might be difficult to gain access to the shop if people can't park. That's how people get down with their books - in the boot of the car," says Eddie.
"The city's so busy, even Gibson street is busy," adds Ian.
"This is a wee quiet oasis in the city, and all the students love us. We're the last bohemian area left in Glasgow."
To follow the progress of the Save Otago Lane campaign, visit their website