What’s the best central mystery in a TV show?

Submitted ⁨⁨4⁩ ⁨weeks⁩ ago⁩ by ⁨bOt@zerobytes.monster⁩ to ⁨television@zerobytes.monster⁩

https://www.reddit.com/r/television/comments/1wauuro/whats_the_best_central_mystery_in_a_tv_show/