One new year eve, the world changed as a powerful system attached itself to everyone. Its abilities rendered everyone speechless as the line between fantasy and reality blurred to non-existent. It's sudden appearance without any previous warning left rooms for many thoughts and theories.

Initially, humans refrained from using it. Afraid of triggering something unknown.

However, with the allure of otherworldly powers sitting right before them, just how long can they resist?

The real tragedy started when someone discovered that by killing other living beings, they 'level up' and become stronger. The spark was lit as tensions began to rise among countries and the peoples within.

And then came the final straw that broke the camel's back.

An old man became young after killing a few people to level up. This fact became widespread in a matter of days throwing the world into chaos. The society as we know it just fell overnight.

While the people and the rulers struggled to bring order to a deranged world, Joe, a murder convict was fighting his own battle to survive a massacre in an abandoned prison in a hidden island.

Can he survive and get out safely!? Or would he succumb and become someone else's 'EXP'?