John suddenly returns home after being abducted and spending 6 years on Franesh, another world. Now he's home and he's brought the "Quest System" along with him. This "Quest System" allows those with it to complete quests assigned by the system to earn EXP and even Attribute Points. Sounds cool right? Except, now dungeons are appearing all over the world and only a few people that were summoned to other worlds, and returned from them, have the power...