Anthony Horowitz
Tim Diamond, the world’s worst detective, and his brainy younger brother Nick, in the Diamond Brothers novellas for children:

The Falcon’s Malteser (1986)
APA: Just Ask for Diamond (1988)

Public Enemy Number Two (1987)

South by Southeast (1991)

The French Confection1,2 (2003)

The Blurred Man1,2 (2003)

I Know What You Did Last Wednesday1,2 (2003)

The Greek Who Stole Christmas2 (2007)

Sherlock Holmes mysteries sanctioned by the Conan Doyle estate:

The House of Silk: A Sherlock Holmes Novel (2011) [review]
Finalist 2012 Macavity Award for Best Mystery
Finalist 2012 Nero Award

Moriarty (2014)

Alex Rider, the teenage nephew of a former British secret agent [YA]:

Stormbreaker3 (2000)

Point Blanc4 (2001)

Skeleton Key5 (2002)

Eagle Strike6 (2003)

Scorpia (2004)

Ark Angel (2005)

Snakehead (2007)

Crocodile Tears (2010)

Scorpia Rising (2011)


The Killing Joke (2004)

Trigger Mortis (2015) [James Bond]