Ancient Knowledge

Ancient Knowledge is the third quest issued to the player by Dr. Patient. When the mission is completed, the player receives 2500 coins.

Mission description
"The Secret Door Finder isn't working! Expert advice is required!"

Overview
After the player retrieves the Secret Door Finder in the previous mission, the zombies are unable to find a way to activate it. Dr. Patient hence tells the player to seek out Zen Sensei, who can advise the player on how to use the finder. Zen Sensei then directs the player to find the Scroll of Instruction. However, once the player finds the scroll, the chest it is on reveals itself to be a Marigold, which promptly escapes. Once the Marigold is defeated the player can pick up the scroll and return to Zen Sensei. After talking to Zen Sensei, the quest is completed and the player receives their reward.

Guide
The Scroll of Instruction can be found in the area beside the plant base, past the Town Hall. The Proximity to Scroll meter should be a giveaway to where the scroll's general location is, but locating the exact place where it lies can be slightly more tricky. Look out for the usual glowing aura that signifies an object that can be interacted with.

The Marigold can be hard to deal with, as it has to be chased through the tight corridors of the suburbs. Following the Marigold can be a tricky task, as the player needs to know how to space themselves correctly. Avoid getting too close, as the Marigold can stun the player and make its escape. Once the Marigold is defeated, the scroll can simply be picked up and brought back to Zen Sensei.

Zombie choice
Imps, Engineers, and Scientists are all good choices for this mission, as they can reliably hunt down the Marigold and dish out enough damage. Imp's natural running speed and double jump are both helpful, as it allows the Imp to take shortcuts to close the gap between the Marigold and the player. However, using the Z-Mech is not recommended, as it can be difficult to navigate and chase the Marigold.

Engineers can use their Jackhammer to attain similar speeds, and their reliable splash damage makes it easy to continuously deal damage the Marigold, whittling down its health. As for Scientists, they run quickly and can use Warp to get closer, but do bear in mind it is risky to use Scientist's full close-range damage, as the Marigold can use its stun attack to cripple him. As such, variants such as the Zoologist that focus heavily on close-range interactions are not recommended.