Opening Dangerous Gates

The Grand Magic Games are over and Fairy Tail is busy! and a certain Celestial Mage is sick of only getting perverted job offers. Until one comes in that isn't, and it requires a S-Class mage with a few tag-alongs to get Lucy's hands on a mysterious black key that looks a lot like a Death God to her.. Wait.. There's something else here too.. Read to find out! [multiple characters!]