Yea quest 5 is one of the last quests I did. After 5 you can do quest 10 if im not mistaken. I hope I have my numbers right lol. --- HeartGold FC: 0217 3044 5646, Nickname: Canoli (Use this one) Platinum FC: 4254 8466 5445, Nickname: Canoli
This quest is at the ending of the main story. Post-ending. Ride Entei on Mitonga Road to smash boulders and up a slope, turn left you will see a tree. Make sure you have a pokemon with tackle field move like 1 or 3. Have that pokemon tackle the tree. A red berry will fall. Fly on Latias/Latios back to Cocona Village, go to Brooker's shop and give the red berry to Brooker. Quest Cleared. Watch a scene between Pros. Hastings and Brooker.