City Spies Series by James Ponti
This series is recommended for middle schoolers.
City Spies
City Spies: Golden Gate
City Spies: Forbidden City
City Spies: City of the Dead
City Spies: Mission Manhattan
City Spies: London Calling
Soon to be released: City Spies: Europa
Recommended Books for High Schoolers
The Inheritance Games
The Hawthorne Legacy
The Final Gambit
Ace of Spades
Firekeeper's Daughter
The Naturals
Killer Instinct
All In
Bad Blood