Returning for the Easter event are the Party Crashers. A group of possibly hostile invaders have taken up residence on our event island. Fortunately, someone has already build a bridge from the island to the mainland, allowing troop access to these invaders.
Alternately, rather than attacking the invaders' camp, you can get a friend to bribe them into leaving. The buffs for this are made in the provision house, and can only be applied to another player's island.
Besides the normal troops, there are additional leaders that may also be present in the invasion camp. They require specific buffs in order to get them to leave peacefully.
While it is possible to simply kill the invaders with troops, there is an achievement both for removing the camps and using the buffs on other players. So, if you wish to get all the achievement for the event, you will need to work with others similarly to killing golems on other player's islands.