Take your pick. I'll talk about any of them.
Let's look at divination spells.
Divinations:
1st-level caster
Detect Poison - We have ways in the Real World of detecting poison easily enough, but people still get poisoned. Heck, most poison is *labeled* as such, but people still get poisoned.
Detect Magic - The PCs in my campaign just did a detect magic on a rampaging treant and learned that he has 5
bestow curse spells and 1
command plants spell on him, but this didn't "ruin" the encounter and adventure. In fact, I was expecting/counting on them finding out this information.
Detect Evil - Considering that [arguably] a third of all humans could be evil aligned, this doesn't solve any mysteries or convict any criminals. If a campaign mystery is held together by a fragile veil of not knowing who the one evil guy is in the crowd, then the DM's mystery skills are very weak.
3rd-level caster
Augury - An 75% chance to know weal or woe about an action in the next 30 mins? Not *real* useful as a dependable tool.
Detect Thoughts - Needs 3 rounds (~18 seconds) minimum of concentration on the subject (area), and the subject gets a Will save. I've witnessed this spell used often in actual game play, and it is not mystery-breaking. Surface thoughts are not "the plot, method, and intentions" of an individual.
Locate Object - A range of ~500' is not useful unless the caster is already pretty much right on top of what he is looking for. To look for a specific item, the caster must have already seen it -- not real useful for finding the McGuffin in the Deadly Dungeon. And a thin sheet of lead blocks it -- and most *all* divinations. Lead coatings should be standard for lockboxes, vaults, and most sensitive areas.
5th-level caster
Clairvoyance - Again, a range of ~500' is pretty limiting. You could just as easily send in the rogue to look around.
Speak With Dead - No more real effective than a modern-day autopsy, but less effective if the creature is a different alignment than the caster - gets a Will save.
Tongues - I wonder how just about every species knows the Common tongue? Might have something to do with this spell. I had an adventure that *required* the PCs have this spell or comprehend languages to "solve" it. In another adventure, two PCs actually spent skill points in a new language even though two other PCs had
tongues usually prepared -- knowing the language always is better than knowing it for an hour.
7th-level caster
Discern Lies - We have lie detectors in the Real World, but that hasn't put a stop to deceipt and fraud. This would be used often in important D&D court cases, but 7th-level casters are not common.
Divination - An 82% for a short phrase or cryptic rhyme/omen on something within one week. Could help some planning, but definitely won't solve problems or reveal sure answers.
Locate Creature - See
locate object above. Plus this can be foiled by
mislead,
nondetection,
polymorph, and even running water.
Scrying - With the Will save for the target, this is not easily done on BBEGs. The PCs in my campaign were recently requested to sneak into a BBEG's lair and get a "body part" (leaf of an elder treant) so the BBGGs could scry on the BBEG. This adventure *relied* on a D&Dism as its purpose. Plus the PCs had to *
teleport* into and out of the dungeon -- hows that for using D&Disms to make the adventure?.
9th-level caster
Commune - 9 yes or no answers. D&D dieties are not omniscient, and they don't know things that don't exist (printing press?). There are a number of story hours on this board that show
commune often leads to more questions than really confirm any answers. The PCs in my campaign once had a magic item that would answer 3 yes or no questions per day, but they rarely knew just what questions to ask.
Contact Other Plane - A very complicated, risky, and unpredictable spell.
11th-level caster
Legend Lore - Days to weeks to cast.
13th-level caster
Greater Scrying - As
scrying above, just lasts longer.
15th-level caster
Discern Location - To find a creature, you must have seen it or have some item that belongs to it. To find an item, you must have touched it. Not to mention *15th-level caster*! And knowing a creature/objects "location (place, name, business name, building name, or the like), community, county (or similar political division), country, continent, and the plane of existence" is not really exact enough to teleport directly to him. Plus a
mind blank blocks it for 24 hours.
So, I don't really see a game-breaking or mystery-breaking problem with any of the common divination spells. If the mystery is as simple as "the butler did it", or the BBEG always hangs out in his throne room waiting for the PCs to scry/locate him, then the DM needs to put a little more thought into the game.
Quasqueton