If you’re stuck in the Bank case in Detective Duck, this walkthrough will guide you through every clue, code, and hidden mechanic needed to crack the vault mystery and identify the real criminal. I’ve played through this case step by step, and once you understand how everything connects, it becomes one of the most satisfying mysteries in the game.
Detective Duck The Bank Walkthrough – Vault Case Solution
Let’s break it down in a clean, logical way.
Step One: Collect the First Key and Unlock the Back Room
As soon as the case starts, look around the starting area and click on the object that gives you your very first key. This key opens the nearby locked room.
Once inside, read the note carefully. It tells you that another key is hidden behind the clock. Interact with the clock to obtain the Water Tank Key.
Use the Water Tank Key on the water tank to receive a Key Card, which is required to enter the Staff-Only Area.
Step Two: Enter the Staff Area and Use the Authentication System
With the Key Card in your inventory, open the Staff-Only door.
Inside, you’ll need two things:
- A USB Drive, found right next to the board.
- A secret code revealed using the UV Light.
When you shine the UV light on the correct area, you will see the code 440.
Insert the USB into the authentication system and enter 440 to unlock the door.
Step Three: Storage Room Puzzle and Code Mechanism
After entering the newly opened door, you’ll find the Storage Room Key. Use it to access the Storage Room.
Inside, use the UV Light again to reveal the code 1863. This code isn’t typed normally — it must be entered using a color-based logic puzzle.
To input 1863, press the buttons in this order:
- Red (represents 1)
- The button that represents 8
- The button before Yellow (represents 6)
- Green (represents 3)
When done correctly, the door opens.
Step Four: Book Puzzle and Vault Code
Pick up the Scissors inside and cut open the boxes. You will uncover three books that reveal the first three digits of the vault code:
- First digit: 6
- Second digit: 9
- Third digit: 2
Now cut open the last box. A note tells you the fourth digit is hidden in the Consultation Room.
Head there and use the UV Light again to reveal the final digit: 0.
Your full vault code is: 6920
Enter it to unlock the vault and collect the key inside.
Step Five: Access the Surveillance Footage
Go to the Tax Office using your newly collected key. Inside, pick up the Remote Control.
Return to the Consultation Room and use the remote to turn on the surveillance screen.
The footage reveals:
- A truck leaving the scene at 2 AM
- The number plate: AA000BN
Step Six: Identify the Criminal
Enter the truck number plate into the suspect system.
This leads directly to Mr. Sterling, the bank manager.
Vote for Mr. Sterling to complete the case — he is the real criminal behind the vault robbery.
The Bank case in Detective Duck is all about paying attention to details, using your UV light wisely, and understanding puzzle logic rather than rushing through rooms. Once you learn how codes, colors, and books connect together, this mystery becomes both smooth and rewarding to solve.
If you’re planning to master every Detective Duck map, learning this case properly will make future investigations much easier.