An Intriguing Grimoire

What is this? This quest An Intriguing Grimoire is started by the item Mysterious Grimoire - that you can turn in with the Darkmoon Faire whenever it is in town.

How do I get it? In order to be eligible to loot Mysterious Grimoire, you must have the [item=71634] in your bags inventory - which can be obtained in one of two ways:

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• Receive it as a reward from Gelvas Grimegate after completing The Darkmoon Faire for Alliance or The Darkmoon Faire for Horde.
• 
  
• Receive it from Selina Dourman just by talking to her, she stands at the first tent on the left-side of the entrance to the Darkmoon Faire.
  Note: if you have The Darkmoon Faire quest in your quest log, Selina will not offer to give you the guide - you will either need to drop the quest and speak to her again or simply hand in at which point you get the guide anyway.
• 
  

Where do I get it? Ornate Weapon only seems to drop from various level-appropriate 5-man dungeon bosses (mostly humanoid caster-types). Drop locations will continue to be updated as they are confirmed. If you are level 85, the bosses that may drop Ornate Weapon for you are highlighted in bold:

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• Lady Anacondra -- Wailing Caverns (dungeon level 17-20)
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• Lord Godfrey -- Shadowfang Keep (dungeon level 18-21)
• 
  
• Bloodmage Thalnos -- Scarlet Monastery Graveyard (dungeon level 31-34)
• 
  
• Arcanist Doan -- Scarlet Monastery Library (dungeon level 31-34)
• 
  
• Darkmaster Gandling -- Scholomance (dungeon level 40-43)
• 
  
• Hydromancer Velratha -- Zul'Farrak (dungeon level 46-49)
• 
  
• Jammal'an the Prophet -- Sunken Temple (dungeon level 52-55)
• 
  
• Emperor Dagran Thaurissan -- Blackrock Depths (dungeon level 53-56)
• 
  
• Grandmaster Vorpil -- Shadow Labyrinth (dungeon level 67-75 and 70 heroic)
• 
  
• Jedoga Shadowseeker -- Ahn'kahet: The Old Kingdom (dungeon level 73-75)
• 
  
• Novos the Summoner -- Drak'Tharon Keep (dungeon level 74-76)
• 
  
• [npc=26530] -- [zone=4100] (dungeon level 79)
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• Jedoga Shadowseeker -- Ahn'kahet: The Old Kingdom (dungeon level 80 heroic)
• 
  
• Novos the Summoner -- Drak'Tharon Keep (dungeon level 80 heroic)
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• [npc=26530] -- [zone=4100] (dungeon level 80 heroic)
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• [npc=39425] -- [zone=4945] (dungeon level 85 and 85 heroic)
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• Archbishop Benedictus -- Hour of Twilight (dungeon level 85 heroic)
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• Lord Godfrey -- Shadowfang Keep (dungeon level 85 heroic)
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Why do I want it? There are several reasons that you may want Mysterious Grimoire:

• 
  
• Receive 10 Darkmoon Prize Tickets upon handing it in - these tickets allow you to purchase mounts, pets and other collectibles whenever the Darkmoon Faire is on.
• 
  
• Receive 250 reputation (or more depending on your racial/guild bonuses etc) with the Darkmoon Faire - great for anyone who is either a rep junkie or is working towards The Insane title awarded by the Insane in the Membrane achievement.
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• Having completed this quest will count towards the achievement Darkmoon Despoiler.
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• Gold gold GOLD - since Mysterious Grimoire isn't BoP (bind on pickup), it is tradable and sellable via the auction house. If you don't care about the above three points, then you can profiteer from someone who does!
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What else do I need to know?

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• High level characters can no longer are not supposed to be able to farm lower level dungeons for this one since a recent hotfix. This should now only obtainable in level-appropriate dungeons (though there continue to be reports of 85s picking up Mysterious Grimoire in low level dungeons), and as always, success is at the mercy of RNG.
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• The quest can only be turned in once per Darkmoon Faire. You can certainly collect more Mysterious Grimoire, however if you've turned in for the current faire, you'll have to wait till it's next in town.
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• Mysterious Grimoire can be looted anytime - that is to say, the Darkmoon Faire does not have to be currently on in order for you to be able to find these puppies.
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What other Darkmoon Faire drops are there?

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• Fallen Adventurer's Journal -> The Captured Journal = 5 x Darkmoon Prize Tickets
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• Banner of the Fallen -> A Captured Banner = 5 x Darkmoon Prize Tickets
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• Captured Insignia -> The Enemy's Insignia = 5 x Darkmoon Prize Tickets
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• Imbued Crystal -> A Curious Crystal = 10 x Darkmoon Prize Tickets
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• Monstrous Egg -> An Exotic Egg = 10 x Darkmoon Prize Tickets
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• Ornate Weapon -> A Wondrous Weapon = 10 x Darkmoon Prize Tickets
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• Soothsayer's Runes -> Tools of Divination = 10 x Darkmoon Prize Tickets
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• A Treatise on Strategy -> The Master Strategist = 15 x Darkmoon Prize Tickets
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Please keep in mind that the quest is not repeatable during one DMF festival. After you complete the quest you cannot get it for the second time, as it states when you use an item for the second time "You have already completed this quest". In other words - you can do the quest once every month.
Now, to all the naysayers, Blizzard has confirmed that these quests are to be repeated each month. Source
They have also stated that the quest drops that happen in the dungeons/raids/BG’s happen all the time, even if the faire isn’t in town. Source

Updated for mop and it looks like there are no drops in [zone=5918]. According to the wowhead, A Treatise on Strategy drops in heroic mode, and the other items drop in normal modes off the respective boss. I.e.: Ornate Weapon drops in normal and not heroic.

I've compiled a easy to see table of where each item for Darkmoon Dungeoneer can be found to get the most bang for your regular/heroic dungeon queues since Blizzard "fixed" the drops so that [faction=909] monthly quest items can only be looted in level appropriate dungeons. This is ordered in alphabetical order, with the instances that drops the most items for DMF items towards the top.

Notes:
I'm keeping the level 80 and 85 data for people who have not upgraded from the Battlechest and Cata to MoP.
If you find that a boss drops something not listed here. Leave a reply and I'll add it in, eventually.

Mists of Pandaria

Imbued Crystal

Monstrous Egg

Mysterious Grimoire

Ornate Weapon

A Treatise on Strategy

[zone=6182]

[npc=61398]

[npc=61398]

[zone=6052]

[npc=58632]

[npc=58632]

[zone=6109]

[npc=3977]

[npc=59223]

[npc=59223]

[zone=6066]

[npc=59080]

[npc=59080]

[zone=5963]

[npc=56717]

[npc=56717]

[zone=5956]

[npc=56439]

[npc=56439]

[zone=5976]

[npc=56636]

[zone=5918]

Cataclysm

Imbued Crystal

Monstrous Egg

Mysterious Grimoire

Ornate Weapon

A Treatise on Strategy

[zone=4945]

[npc=39732]

[npc=39425]

[npc=39378]

[zone=5844]

[npc=54938]

[npc=54968]

[npc=54938]

[zone=5396]

[npc=43614]

[npc=44577]

[npc=43612]

[zone=4926]

[npc=39698]

[npc=39705]

[zone=5789]

[npc=54432]

[npc=54432]

[zone=4950]

[npc=40177]

[npc=39625]

[zone=209]

[npc=46964]

[npc=4278]

[zone=5035]

[npc=43875]

[npc=43878]

[zone=5004]

[npc=40586]

[npc=40765]

[zone=5788]

[npc=54853]

[npc=54969]

[zone=1581]

[npc=47626]

[zone=5088]

[npc=43214]

Wrath of the Lich King

Imbued Crystal

Monstrous Egg

Mysterious Grimoire

Ornate Weapon

[zone=4494]

[npc=29310]

[npc=29308]

[zone=4196]

[npc=27483]

[npc=26631]

[zone=4265]

[npc=26794]

[npc=26723]

[zone=4277]

[npc=29120]

[zone=4416]

[npc=29306]

[zone=4272]

[npc=28923]

[zone=4264]

[npc=27975]

[zone=4813]

[npc=36658]

[zone=4100]

[npc=26530]

[zone=4415]

[npc=31134]

[zone=1196]

[npc=26693]