The EthPhoenix Developers (
https://www.ethphoenix.io) are offering a ~$500 reward for solving a puzzle related to the announcement of new feature they are planning to release for their Ethereum dApp.
The puzzle appears to be partly cryptographic in nature and partly literary, and the clues are spread across the EthPhoenix dApp ecosystem (e.g.
https://www.pyrmex.com).
If you're a puzzle solver who likes a good mystery, this treasure hunt might be up your alley. The best place to get started is the EthPhoenix discord channel:
https://discord.gg/FNQbGjJ to join other sleuths who are trying to crack the puzzle.