It called Ireland Hopping!
As in the previous chapter you will get a loot item upon completing every job, so you are able to get 4x of this mastery item.
You will need exactly 326 Pints of Stout and 7040 energy to finish it from A to Z.
Here are the screenshots.. 
We will have the mastery item for each job mastered! So, once again, this is not a glitch!
The mastery item ie Black Irish is a very good weapon.
Get the weapon now, my friends! Do your jobs and complete the mission..
