March 23: Anti Corruption Day

When a serial killer brutally murdered, police officer receives a call from anonymous. He addresses himself as the killer and he tells that he has kidnapped another three persons and locked in an isolated place. They have been put in deathtrap. Killer challenges police to find them...Otherwise they will also be killed brutally and puts a time limit of 4 hours. Now the police officer must find them before given time..? Will he succeed? How could it is possible to find them in the big city without address?