This quest is available once you explore the piece of land adjacent to where Black John appears. Note: Black John will not appear until after you tap the area to 'complete' exploring it and turn it into choppable trees.
These pirates are literally plagued! We can't let them land!
- Chase off Black John or he'll give us the plague!
That was a close one! We have to be careful.
- 750 coins.
Competing this quest unlocks Shark Ahoy!.