The Secret World of Og is a children's adventure about 4 children who venture into an underground cavern beneath their playhouse to look for their lost baby brother. There, they discover a land of little green people who are enamored by the world above but won't allow anyone to leave their cavern for fear they might "tell".

Just an ordinary boy from the Sofia suburbs becomes the first bulgarian undercover cop. Forced by his father when he was young to lie and cheat, Martin becomes the perfect liar. That skill, and also the hatred of the 'underworld' makes him the perfect match for a dangerous mission - to infiltrate the crime organisation of a rich and powerful businessman. While infiltrating and living in fear of being uncovered, Martin falls in love with the most inappropriate woman - Djaro's girlfriend, Suni. Just when he gains the trust of the mobsters, it appears that the real enemy is in the police. Martin is alone against all, facing difficult decisions.

It is a long told story about underground of Istanbul streets.