Extreme Str8ts Puzzle #67 was very difficult, requiring the use of advanced strategies. A key step was eliminating the candidate 3 from cell H9, revealing a 9 in E1. This opened up the puzzle, allowing hidden pairs/triples and X-wings to be found. XY-chains were also useful, removing candidates from cells like H4, J3, and H5. Once these strategies were applied, the puzzle became soluble, with the solution found through standard elimination techniques.