As you follow the road northward, you spot Suicune yet again, standing out in the waves. It runs off like usual before Eusine shows up with a clue. He believes that the legendary beast prefers "a hilly place near water... somewhere north". This is the final time it will flee upon meeting you; from this point on, you may return to Cerulean Cape to challenge it to a battle.
Route 13 is comprised almost entirely of a large maze of fencing. On the way through the maze, be on the lookout for hidden items.
The lone building belongs to the Fishing Guru's younger brother. Convince him that you like fishing to receive the Super Rod, the best fishing rod! This makes it possible to reel in more than just Magikarp and Tentacool, so be sure to try it out everywhere.