Harry Potter and the Veil of Mystery is the first in the "Post-OotP" trilogy by the author semprini. The next two stories are Harry Potter and the Ring of Reduction and Phoenix Intuition. You can find the stories at semprini's ff.n author page. Note that the fics Harry Potter and the Antiquity Link and Harry Potter and the Amulet of the Moon are not part of the series and constitute a separate post-Deathly Hallows arc.
There are some spoilers for Harry Potter canon through to Order of the Phoenix.
Harry Potter and the Veil of Mystery provides examples of:
- Aesoptinum: Harry Potter's ability to use the magic of love to generate shields against the Unforgivable Curses is rooted in a mindset that requires a state of mind akin to that attributed to Jesus Christ's "they know not what they do" level of forgiveness.
- Ascend to a Higher Plane of Existence: Through a very unique set of circumstances, Dumbledore finds a way to introduce Harry into the afterlife in a limited way. This not only allows Harry to get critical information in a way that would otherwise be impossible, but facilitates the reintegration of Snape by reversing the Cleansing, as well as giving his friends closure. As an example, Neville's grandmother and his parents are able to give him final messages.
- Big Bad: Voldemort. In spades.
- But Not Too Gay: Blaise Zabini is gay in this series, but very little about his relationships is discussed.
- Chekhov's Armoury: It really is like Chekhov's Small Arms Factory in these fics. Everything the author introduces as a special skill or special item, even if not obvious, gets used in the fic arc to accomplish something. Example: Draco Malfoy smuggles in some artifacts. The characters briefly discuss this at one point in the fic arc. Some chapters later, Draco Malfoy uses one of them to kidnap Ginny Weasley.
- Cool Teacher: Harry Potter. He becomes the Defence Against the Dark Arts teacher in Veil of Mystery and Ring of Reduction. Albus Dumbledore, as well.
- Cynical Mentor: Severus Snape. After killing his mother, he had a My God, What Have I Done? moment. Snape was sufficiently regretful to go to Dumbledore and try to redeem himself by means of spying for him. Afterwards, Dumbledore was able to treat the symptoms of the Cleansing, but not cure the underlying cause. Finding the ultimate cure fell to Harry Potter. Additionally, Snape's point of view, in contrast to some of the more nuanced moral perspectives offered by others, is extremely pragmatic based solely on the goal of defeating Voldemort. Because of what he has to go through, he takes on shades of being an Anti-Hero.
- Deal with the Devil: Voldemort purposely mutilates the minds and souls of his Death Eaters in an act called the Cleansing, which removes the ability to feel happiness except through violent acts. Snape has suffered this and wishes to have it reversed, but Dumbledore was unable to effect this. Harry Potter eventually figures out how to reverse the process. Voldemort crows about how he even did this to himself and gleefully gloats that he believes this will help him win against Harry. Draco Malfoy is the counterpoint to Snape's wish for redemption as he happily accepts the Cleansing and refuses to have it reversed even when Harry offers to do this for him. He's not a nice person in this arc.
- Grey-and-Gray Morality: There's moral ambiguity all over this series. Harry's initially relatively black and white moral system takes on a leavening of grey as he tries to reconcile the real-world acts he sees with the moral code he's developed, which was in response to regarding the abyss of casting the Cruciatus Curse on Bellatrix Lestrange in Order of the Phoenix. Neville also ends up discovering the problems with He Who Fights Monsters when he encounters Lestrange.
- HeelFace Turn: Pansy Parkinson spies for Harry in Slytherin House and provides a crucial warning to Harry, saving his life when a student under the Imperius Curse tries to use a machine-gun to kill Harry in the Great Hall.
- Heroic Sacrifice: A prominent example is Dumbledore purposely throwing himself through the Veil in the Ministry during a battle with Voldemort, assisting Harry in his task to defeat Voldemort once and for all.
- Moral Dilemma: Many characters in this fic arc discover truths about themselves, some pleasant and some very unpleasant, through engagement in moral dilemmas, or in some cases, the blowback from decisions they made in canon or in the fic arc. Example: Hermione Granger's decision to forbid Rita Skeeter from writing any articles of any kind eventually causes a very nasty situation for her and her friends.
- Not That There's Anything Wrong with That: Harry finds himself confronting some internalized homophobia, and having to consider it in light of his new magical abilities (which are fundamentally based on embodying a deep respect for all beings) when he finds out about Blaise Zabini, and then witnesses the reactions from Severus Snape (loathing due to having been abused as a child), Pansy Parkinson (uncomfortable bare tolerance) and Hermione Granger (unconcern with the fact).
- Old Master: Albus Dumbledore. He's not so much the Eccentric Mentor type in these stories.
- Right Makes Might: Mostly averted, but it exists in a small measure when Harry comes up with the "Imperius Charm" which allows him to manipulate people in very specific circumstances. His acts can be justified on the basis of some woo-woo involving the nature of the power behind the magic of love and because, by authorial intent, it paves the way to discovering how to reverse the Cleansing.
- Shipping: Fairly bog-standard, but there's a few surprises. Harry Potter dates Ginny Weasley, Ron Weasley dates Pansy Parkinson, and Hermione Granger dates Neville Longbottom. It's mostly kept in the background, but the romantic trials and tribulations of the teenagers do occasionally provide fodder for the Moral Dilemma issues.
- Stock Aesops: Many of the older characters who speak to Harry often to do to illustrate moral or ethical messages. As an example, Hugo Brantell, a quasi-psychic news reporter, explains the "facts of life in the media" in order to explain to Harry why he needs to keep engaging with the public, even though he has a very strong distaste for the media generally due to the abominable way the Ministry and the Daily Prophet treated him during his fifth year at school.