6 individual suspense novels for teens from the series of Adventures of Feluda by Satyajit Ray.
The Blue Set contains following books:
1. Badshahachi Angathi
2. Gangtokmadhil Gadbad
3. Soneri Killa
4. Kailasatil Karasthan
5. Royal Bengalche Rahasya
6. Case Attachi Casechi