Through Mirkwood is the third campaign from The Hobbit Kingdoms. It rewards the player with Swift Stones.
Go to your Sage’s Tower > Relics > scroll down and check your Swift Stones. These stones can be used from your City Guardian (the statue from the middle of your city) for “Activation”, an upgrade that will increase the training speed for your troops.
The good news is that Through Mirkwood will not decimate your might. The last camp from the last map has 38k might which is very small compared to Avenging Moria which has 70k might at the second map.
Tips for farming
Attack only the first camp from each map to farm Light Metal (to minimize your troop loss). When you got enough Metal, start farming the last camp from each map for Ambers. Use Tier 3 troops if you don’t want to scroll / write two times (when sending the troops, one time for tier 1 and one time for tier 3).
If you haven’t finished this campaign, you should definitely do it because the next campaign from a future update might be locked until you finish Through Mirkwood.