"The door finder is on, but it's out of power. Charge the door finder so you may find the secret entrance to Dr. Zomboss' Lab."
This mission is a Special Ops in Sandy Sands, where the player must defeat Sunflowers to charge the Door Finder. Five waves must be completed in order for the player to finish the quest, with the third wave being a special wave unique to this mission and the final wave being a boss wave.
The third wave, named Radiant Sunlight, is a wave consisting primarily of Dandelion Weeds and Mystic Flowers. The final wave contains a single Sunflower Queen, who must be defeated to finish the quest.
Dr. Zomboss tells the player to charge the Door Finder by defeating Sunflowers, every Sunflower vanquished yields 1% of charge. However, this proves to be not enough, and by the fifth wave, Dr. Zomboss instructs the player to defeat a Sunflower Queen to get more charge.
Because of the nature of this mission, the waves are comprised mostly of Sunflowers, who should not be too hard to defeat due to their lower health. However, it is advised to take them out one a time so they cannot constantly heal one another.
The third wave is filled with Dandelion Weeds, which will explode if they get close to the player. Thus, Engineer variants are highly recommended for at least one of the four characters, as their splash damage will dispose of the crowds with ease.
The fifth and final wave will contain a single Sunflower Queen. As with other times she appears, remember to take out the Mystic Flowers she summons immediately, as they can heal the Sunflower Queen, making it difficult to vanquish her. However, as there is only one Sunflower Queen and the rest of the plants aren't very threatening, it should be safe to focus all firepower on the Sunflower Queen and her summoned Sunflowers.