Challenging Puzzle Subscription

GMS consists of a monthly mailing in which you are tasked with locating fragments of Einstein's brain. The mailings take the form of a single, multi-step puzzle of above average difficulty. Because each month's puzzle is focused on a single theme/item, there could be a mailing which misses the mark for you. However, I have found those misses to be few and far between. In fact, one of the early mailings is hands down the best single puzzle I've encountered from these subscription based puzzle boxes. I would recommend that any who appreciates complex and intricate puzzles give GMS a try.