Laboratory · Puzzle walkthrough
Fly Puzzle: 7425 Chest Code
Quick answer
The fly chest code is 7425: read the four hanging strips from left to right, with 7, 4, 2 and 5 flies. Place the strips on the office wall first, then enter those counts at the chest in the white-cat room. Collect the night-vision lens, access card and egg.
On this page
Before you begin
Before you begin
- Finish the chameleon red-box puzzle and take its key.
Follow the clues
- 01
Unlock the drawer containing the fly strips
Use the red-box key on the top drawer in the computer area. Collect both the sticky strips and the pliers. The strips reveal this code; the pliers are needed for a different, later door-power puzzle.
You’ll know it worked: Both tools are in your inventory.
- 02
Hang the strips above the rubbish bags
Return to the office and inspect the wall below the bottle shelves. Apply the sticky strips there. Count each strip separately from left to right: seven, four, two, five.
Count each strip separately; do not add the flies into one total. Game image © Dark Dome; source capture by Play Games Wiki. View the source walkthrough ↗ You’ll know it worked: Four groups of flies are visible.
- 03
Enter the four counts on the chest
Go to the white-cat room and open the chest’s padlock view. Set its four fields to 7, 4, 2 and 5 in that order. This chest is separate from the cat cabinet, whose two-row answer is 47 / 35.
You’ll know it worked: The fly chest opens.
- 04
Collect the three rewards
Take the camera lens, the scientist’s access card and the egg. The lens enables the camera clue, the card supplies the computer password and door credential, and the egg belongs in the later duck nest.
You’ll know it worked: You have the items needed for the camera, computer and duck sequences.
If you’re still stuck
Is 7425 the same as the cat cabinet code?
No. The fly chest has four left-to-right values, 7425. The cat cabinet is a two-row arrangement, 47 above 35. Check which lock you are looking at.
The strips are still in my inventory. Where should they go?
Use them on the office wall above the rubbish bags, below the shelves. They must be hung to reveal the fly counts.
Why does the camera still not show a clue after I take the lens?
Attach the lens to the recorder, put the recorder on its tripod and switch off the room lights. The camera/computer guide covers the remaining sequence.
Sources and scope
Based on public mobile walkthroughs and the linked game captures. We have not played through this sequence ourselves or verified Steam-version parity. Checked 2026-09-23.