Rally Vincent and Minnie May Hopkins are just a pair of gun shop owners who do a bit of bounty hunting to make ends meet when a Bureau of Alcohol, Tobacco, Firearms agent comes to them. Using the threat of arresting them for their lack of a retail license for their merchandise and the resulting unpaid taxes, he forces them to agree to cooperate in a sting to break a gun running ring. They have an initial success, but that brings new problems as the ring's leader brings in a merciless assassin to eliminate these new enemies. It will take all their skill, allies and some luck to come out this crisis alive.

　　故事发生在23世纪的月面都市“伊甸”。地球毁灭后，当时的人类移居到了月球，为了伊甸的繁荣月共和国剥夺了伊甸居民的两种自由。其一，科技研发的自由。其二，去地球的自由。居住在伊甸的少年们经历重重试炼，为了弄清楚被伊甸管理局称为“已经毁灭的地球”的真相，始终追求着真正的自由的故事。