From the Warhammer Herald:
"Hold the ball and you'll get points over time, as well as points for killing other players - more points than you would normally! If you're killed while holding the ball, the other team will get double your normal kill value... and of course you drop the Murder Ball! As with all Murder Ball Scenarios, you will take damage for as long as you're carrying the artifact... power has its price!
Both Realms start this map on opposite sides of the Mourkain temple ruins. At the center of the temple lies the Mourkain Artifact. The swampy terrain and temple provide an impressive backdrop for this Scenario. Players who are swarthy and use their sprint ability wisely will make it to the Artifact first, and gain the upper hand. Teams that stick together and protect the Artifact carrier will find this Scenario easy to win. In a way, Mourkain is reflective of our open field combat in the Marshes of Madness, but with the added satisfaction of chasing down a specific target. Teams that flank and use the whole terrain will be able to shake free the Mourkain Artifact from their opponents grasp. Use the swampy terrain and vines to break line of sight, and always be on the move in this Scenario. Staying still will net you a quick death, and possible loss of the powerful Mourkain Artifact!"