Trey is thrilled to be accompanying his father, influential Chicago businessman T Drummond MacIntyre II, on a trip to Constantinople.

Armed with a suitcase packed full of his favorite tales of super-sleuths and daring detectives, Trey can't wait for his holiday to begin.

So imagine his excitement when, as father and son board the Orient Express, Trey thinks they are being followed by a mysterious stranger.

Surely Trey's been reading one too many spy capers? However, as they make the journey across Europe, Trey's father appears distant and evasive.

Is he simply busy with work, or is something more untoward happening?

When T Drummond MacIntyre II goes missing, Trey is plunged into the secretive and dangerous world of 1920s espionage, trawling the chaotic streets of Constantinople in search of his father's whereabouts.

But while Trey has always dreamed about being a spy, nothing can prepare him for the breathtaking escapades that await him in this exotic and enticing city - Combining the action-packed exploits of Alex Rider, with the historical adventures of Young Indiana Jones, "I Spy" is a gripping story of one boy's fight to find his father.