In the Mekhet clanbook for Vampire the Requiem, the "Dream Visions" merit allows a character to get a small amount of information about other people and places by asking a single yes-or-no question.
Dream Visions (•••)
Effect: More than any other clan, the Mekhet dream. And sometimes, between bizarre, gory, awful dreams of death and transformation and blood, they dream of places they haven’t been to and people they haven’t yet met. Sometimes, during some later night, they find themselves going to those places or meeting those people (Nitokris, Vincent Moon and Elisabeta all dreamed of Frances before they met her, for example).
With this Merit, your character can make use of his dream-visions. The first time (and only the first time) he meets another person or visits a place, the player can make a roll of Blood Potency. If it’s a success, the player can ask one (and only one) question about the person or place, which must be phrased so that it can be answered truthfully with “Yes,” “No,” or “Maybe.” The roll can only be made once regarding any individual, and the roll can only be attempted once a scene (meaning that, for example, if the character meets two vampires for the first time, the player must choose which of them to ask the question about, because he won’t ever get the chance to ask about the other).
Note: Though this Merit is not restricted to Mekhet characters, it is found among the Shadows more often than any other clan.
What are some good general questions to ask with this merit, both for characters and for places?