In 'Unknown Caller', players find themselves in a bustling city as a character who accidentally acquires a mysterious smartphone left behind in a cab. The phone is mysteriously connected to a series of dramatic events involving a secret society, espionage, and shocking revelations. Players must navigate the city, interact with quirky characters, and piece together clues hidden in text messages, photos, and apps to uncover the rightful owner's identity, while avoiding the society keen on retrieving it at any cost. Each decision could lead to new alliances or deadly foes, twisting the narrative based on player choices.