Adventure Island is published by Orion Children's Books. The series is marketed for readers of 8-12, but is also suitable if you are a younger confident reader or would like to listen to the stories being read out loud.  
There are fourteen titles in the Adventure Island series. Each book contains a separate mystery, so you don't have to read them in order, but you might want to start at the beginning; that's where you first meet the characters and there are some themes and sub-plots that develop over the course of the series.  
Several of the books have been translated into other languages, including French, Dutch, Japanese, Portuguese and Bulgarian. 
They are also all available as e-books.

Book One
The Mystery of the Whistling Caves
When Scott and Jack Carter have to stay with their great aunt for the summer they steel themselves for the most boring holiday ever. But then they meet Emily Wild and her loveable dog, Drift. Emily shows them the lighthouse, the castle - and the amazing whistling caves. Legend has it that when the caves stop whistling the castle will be attacked - and that's exactly what happens!

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Book Two
The Mystery of The Midnight Ghost
When Scott , Jack and Emily hear that a film is being made at the nearby manor house they can't resist going to watch. But when the glamorous star of the film vanishes the friends must find out if she has fallen foul of the legendary ghost that haunts the old house . . .

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Book Three
The Mystery of The Hidden Gold
A game of hide and seek in the old Castle Key lighthouse during a violent thunder storm leads to an amazing discovery - a tattered old treasure map! Scott, Jack and Emily can't wait to search for the hidden gold but first they must solve the clues to uncover its secret hiding place.

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Book Four 
The Mystery of The Missing Masterpiece 
When thieves raid the house of a neighbour, Emily, Jack and Scott are ready to investigate. But, strangely, the neighbour doesn't seem to want the thieves to be caught! Undeterred, the friends begin to uncover the truth, but are they getting themselves into serious danger…

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Book Five
The Mystery of The Cursed Ruby
The circus is in town! Full of conjurors, clowns, tightrope walkers and trapeze. But dark secrets lurk beneath the sawdust and smiles. Secrets that might prove impossible to solve!

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Book Six
The Mystery of The Vanishing Skeleton
A string of unusual crimes hits Castle Key and the chief suspect seems to be a skeleton! Scott, Jack, Emily and Drift the dog immediately start investigating, but nothing makes sense. Will the friends finally be defeated by this mysterious culprit or can they uncover the truth…?

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Book Seven
The Mystery of the Dinosaur Discovery
When Scott, Jack and Emily stumble upon some bones in the old quarry, they're convinced they've discovered the gruesome remains of a murder victim! But the bones turn out to be much, much older than that - could they be dinosaur bones? Or are they the last earthly remains of a real dragon? Rival scientists fight to prove each other wrong, while the friends are determined to uncover the truth - with a little help from Drift the dog, of course!

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Book Eight
The Mystery of the Drowning Man
When Scott, Jack and Emily rescue a drowning man from the waves they are keen to hear his story, but their new friend can't remember his own name, let alone how he came to be stranded at sea! Who is the mystery man? Why did he come to Castle Key? And was his drowning an accident - or attempted murder? The friends are on the case - with enthusiastic assistance from Drift the dog - determined to find the truth and solve the mystery of the drowning man.

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Book Nine
The Mystery of the Smugglers Wreck
A research team arrives in Castle Key to explore the wreck of an old smugglers' ship that sank in Pirate Cove. When Scott and Emily dive down to the wreck, Scott glimpses a long lost artefact said to hold the key to a hoard of smuggled treasure. But when the team leader goes back to recover the artefact, it has mysteriously vanished! Was Scott mistaken or is somebody else after the smugglers' loot? Follow Scott, Jack, Emily and Drift on a very mysterious treasure hunt.

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Book Ten
The Mystery of the Invisible Spy
There's a new resident in Castle Key - and somebody is watching him! Scott, Jack, Emily and Drift soon suspect that the new resident is an enemy spy. It explains the bullet-proof glass in the windows of his house. And the MI5 agent who is clearly keeping tabs on him! But what is an enemy spy doing in Castle Key? Can the friends reveal his true identity? And uncover his top secret mission? Join Scott, Jack, Emily and Drift as they investigate a man so mysterious he's almost invisible!

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Book Eleven
The Mystery of the King's Ransom
When a young prince is kidnapped while on a school camping trip in Castle Key, Scott, Jack, Emily and Drift are eager to take on the case. Drift's clever nose is sure to sniff out some clues to the kidnappers - but can the friends rescue the hostage in time?

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Book Twelve
The Mystery of Black Salamander
Scott, Jack and Emily are excited when they are invited to go and watch the testing of a top secret, super-advanced, prototype car. It's just like something out of a James Bond movie - and a secret agent is exactly what's required when the car mysteriously vanishes! Luckily, the friends are on hand to find the car, catch the culprits and save the day - with a little help from Drift the dog, of course!

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Book Thirteen
The Mystery of the Secret Room
When Boomerang the cat disappears into a tiny gap behind the fireplace at Stone Cottage, Scott, Jack and Emily are amazed to discover a secret room that Aunt Kate never knew existed! But what was the room created for? Inside is very little other than an enormous old chest which Jack is convinced must be full of treasure, but what secrets will be revealed when the friends finally manage to open the box?

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Book Fourteen
The Mystery of the Phantom Lights
Something strange is afoot on the moors above Castle Key - sinister noises, lights in the sky and mysterious figures moving in the dark. Are aliens invading, as Jack suspects? Could it be smugglers, as Emily thinks? Or is there another explanation? Scott, Jack, Emily and Drift the dog are on the case!

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