Jasoosi Dunya (The Spy World) is a best-selling series of Urdu spy novels written by Ibn-e-Safi. The first novel, Dilaer Mujrim (The Brave Criminal) was published in March, 1952. The central idea and theme of this novel was taken from Victor Gunn’s novel Ironside's Lone Hand. However, the main characters, Colonel Faridi and Captain Hameed, were Ibn-e-Safi’s own creation.
As mentioned by the author in the introduction to Zameen Kay Baadal, the plots of Purasrar Ajnabee, Raqqasaa Ka Qat'l, Heeray Ki Kaan, and Khoonee Patthar were adopted from various English-language novels. The characters of Professor Durrani from Khaufnaak Hangaama, and Chimpanzee and The White Queen from Pahaaroan Ki Malikaa, were also borrowed from characters found in English literature. The rest of Ibn-e-Safi’s novels have original plots and characters conceived by the author himself.