Honkai: Star Rail features a number of interesting logic puzzles in its quests. One side quest has you questioning suspects to determine the detector thief. Similar to some classic “who is lying” logic puzzles that you might have encountered before!

Here is the Honkai Star Rail detector thief puzzle, and how to solve it:

## Who is the detector thief?

You interrogate the four suspects, and each makes one claim:

- Cook says the helper did it
- Tailor says it wasn’t her
- Merchant says the cook did it
- Helper says it wasn’t him

Swetta also tells you a critical piece of information: **only one of the suspects is lying**. This is all you need to solve it.

## Answer to Honkai Star Rail Detector Thief

The cook is the thief.

Logic:

- Since the cook and the merchant accused two different suspects, one of them must be lying (and therefore must be the thief) and one of them is telling the truth.
- This means the other two are telling the truth, so the tailor and the helper are not the thief.
- Since the cook accuses the helper that we now know is innocent, he must be lying, so he is the thief.

If you get it wrong, you may anger the other suspects, but you will eventually be put on the same path for the same rewards. But it’s always more satisfying to find the correct answer!