Surprised to find there's no review for such a staple card! No Stone Unturned offers some support tutoring ability to help yourself and teammates find setup pieces. However, at only 6 cards searched for 2 resources and an action, no stoned unturned is rarely worth the price of admission unless it comboes with your investigator particularly well (Mandy and Joe Diamond's Hunch deck come to mind).
Choose an investigator at your location. That investigator searches the top 6 cards of his or her deck for a card, draws it, and shuffles his or her deck.
As mentioned by toddwords, this card is expensive at 2 resources. The 5 XP version is amazing but only if you have that much XP available to spend. I sometimes wish there was an intermediate XP version and now there is - sort of: Parallel Fates. Of course, not every investigator with access to No Stone Unturned has access to Parallel Fates and taking Parallel Fates won't get you any credit toward No Stone Unturned but it is an interesting upgrade to consider.