My Books
The Case of the Hidden City


Paris in the springtime - the City of Art and Artists at its loveliest! But it would seem that there is a sinister side to all this beauty. Rumours of a mysterious organisation called The Hidden City are rife, and when not just paintings, but artists and their models too, start to disappear, no one knows what to think.

Out of her country for the first time, Slightly Jones soon finds herself out of her depth as well. Could this be a case our detective-in-training just can’t solve? And will she be lost forever under the streets of Paris?

And suddenly she was up to her ankles in icy water. It was here too! Black and evil-looking, lapping hungrily at her feet. Back! Go back! her body screamed at her but how could she go back?

She made herself go on, feeling with her feet for fear that the unseen floor might suddenly drop away. Her stockings and shoes and skirt were soaked and heavy with the freezing water. She was shivering uncontrollably now and she clenched her jaws so tight they ached, trying to stop her teeth from clattering together. The lantern reflected off the black surface and then she strangled a scream as a huge rat swam at her out of the gloom. Frantically she pressed herself against the dank wall to get out of its way, but it paid no attention to her at all and powered on down the tunnel. She watched it until it was out of sight and then, reluctantly, sloshed forward again.

Even the rats are fleeing. They do that from a sinking ship. But this was worse than a sinking ship. In the open ocean you could at least try to swim, but in a tunnel, once the water got to the ceiling, there was only drowning . . .

…that there are still rats and lapdogs just like the ones in the book, alive and well and living in Paris?  I saw them when I was doing the research!


…that I’m not very good at being deep underground?  But when I visited the Catacombs I was so awe-struck and amazed I really didn’t have time to feel panicky.


…that I named Madame Mini and her husband after the street I stayed on in Paris?

"I think this was a great book and I absolutely love it!!"

NeonMimi: The Guardian


"Overtones of Sherlock Holmes and an authentic Victorian (although Parisian) background. make this an excellent read with plenty of tension as well as highly enjoyable text and entertaining dialogue ... There's a great website to support the books too, at"

Parents in Touch


"Oh hello there lovely book, where have you been all my life ... We're about to become Slightly obsessed!

For ages 8-11, the Slightly Jones mystery books are wonderful, packed with historical detail without feeling too dry and laborious. In fact they're about as rip-roaring as it gets.

The books are backed up by a rather fabulous website so check out more information over at"

Read It, Daddy!


"Paris is a very definite character in its own right in this book, but wonderful though the city is, it has nothing on the delightful Slightly. Her bright enquiring mind and her keen eye for detail allow her to make connections and discover the truths criminals would prefer to leave hidden, and even in moments of dark and deadly peril she never gives up trying. She is a heroine readers could easily imagine having as a friend, and it is to be hoped that Ms Lennon can be persuaded to give us more of her adventures very soon!"

Linda Lawlor: The Bookbag

Here are the answers to the questions in the back of The Case of the Hidden City

Click on a question to see the answer! (Click again to hide it.)

The answer to How many people are thought to be interred in the Catacombs under Paris? is -

c) 6,000,000

True or False?

a) The popular 19th century travel guide, Murray’s Handbook to Paris, tells us that “in the Boulevart Neuf a building near the Barriere d’Enfer suddenly sunk down into a hole 80 ft. deep, which created great alarm, and called public attention to the subject."  He goes on to say that there’s no need to worry, though, because “the whole subterranean region” has been mapped since the cave-in. 

It’s TRUE that buildings sometimes collapsed into the tunnels and caverns under the city.  But it’s FALSE that the miles and miles of passageways and caves under Paris have all been mapped.  To this day, only part of the “subterranean region” is known and recorded.

b) Today many people travel to Paris from Britain by train, going through the Channel Tunnel.  The first proposal for a Channel Tunnel was put forward early in the 20th century. 

FALSE.  Out by 100 years!  As early as 1802, French engineer Albert Mathieu had come up with the idea of a tunnel under the English Channel, lit by oil lamps, with horse-drawn coaches and an artificial island halfway across for changing horses.

c) Because photography is so good now, the tradition of artists copying the masterpieces in the Louvre has mostly died out.  

FALSE.  Copying the original paintings of the greatest artists is still seen as an excellent way to learn.  Artists from all over the world who come to the Louvre to copy the paintings get permission – and the use of an easel – just as they have since 1793.

d) The Mona Lisa has never been stolen.

FALSE.  The Mona Lisa went missing from the Louvre for more than two years!  A man called Vincenzo Peruggia took the picture off the wall on the 21st August 1911 - a Monday – cleaning day at the museum – and walked out of the building with it.  The next day, when the artist Louis Beroud came to work on a copy of the Mona Lisa he was making, nobody knew where the da Vinci painting had gone.  It was hours before the officials realised it had, in fact, been stolen!

e) Paris used to be completely under water.  

TRUE.  Though the last time it was completely submerged was several million years ago, so a bit before the actual city ...

f) In one of Sherlock Holmes' cases, he speaks of "the curious incident of the cat in the night-time."

FALSE. It was a dog. Sherlock Holmes' author, Sir Arthur Conan Doyle, used the phrase in a short story called "Silver Blaze".