Storytelling relies on a few strategies to guide the reader toward a conclusion. Manipulating that conclusion can come in many forms, as you've seen. One tactic that JKR has always kept near at hand is the manipulation of the mystery through outrageous misdirect. Without revealing any names, just look to her most recent foray into mystery writing for an example (semi-spoiler ahead). The killer in her first novel of the series was the absolute last person you could possibly imagine.

"Well...I want you to be surprised," she could say.

Mmm, it seems more like you're fearful that we'll figure it out, so you mislead the reader so severely that it makes the solution unsolvable. Unsolvable riddles aren't mysterious. They're controlling.

"But, Mike," you say, "isn't an author supposed to control the flow of information so the mystery isn't exactly solvable until the end?"

Here's what I think. A good mystery writer should be viewed almost like a stage magician, who sets up their act with subtle tricks, using sleight of hand and audience perspective to implore you into accepting that what you had just witnessed was complex and even impossible to figure out until that very moment. This is typical with books. Like a magician, authors are supposed to be able to pull this off without their audience knowing how the trick was played.

Cursed Child fails at this.

Delphi and Amos

The antagonist of Cursed Child, who we learn by the end to be the heir of Lord Voldemort, was disguised from the get-go. The mere introduction of her as Delphini Diggory defines her identity. If there was any sense that an heir could reveal themselves later in the book, since it was brought up in rumors about Scorpius' birth, the reader was incapable of guessing Delphi as that heir. This is further defined by a confirmation from Amos Diggory that she is a niece of his - a tactic that is certain to achieve the desired result. The reader has faith that if a character is introduced as the niece of a trusted character who has no reason to conceal her identity, then she is. For that reason, she could never even be added to a list of suspects. Which is an underhanded trick by the writers to control your problem-solving reflex, and to keep the identity a secret until they say it's okay. This is controlling and, quite honestly, betraying your trust.

In a normal situation, this sort of "stolen identity" misdirect is easy for any investigator, and thus, the audience, to solve. It plays by the rules of civil society. Ask around, and you'll eventually learn the truth about that person's identity. The basic reasoning behind Cursed Child is not fair, because the use of magic in the story means it doesn't have to follow the same rules. It's an example of manipulation because Delphi confunded Amos Diggory into validating her identity.

Under those circumstances, it removes the possibility of guessing her true identity. This ability to hide in plain sight through magic suddenly throws all laws of normal character behavior out the window. If anyone, at any time, could be confunded (or disguised within someone else's identity through Polyjuice - looking at you Goblet of Fire), it interferes with our ability to understand the mystery we're given until the writer steps back and says, "Ta-da". And rather than invoke cheers, it gets the reader to say, "Whaaa?" And there, in the smattering of applause, are the inaudible sounds of fans grunting internally, because the trust they once had in the writers has quickly become strained.

Delphi's character

And if this ploy wasn't enough to keep you from learning the secrets about Delphi, JKR and Co. introduced her by pouring the foundations of a completely different character into her shoes.

When we first meet Delphi, she's playful. She makes childish jokes about being a thief at the Potter house, looking for Chocolate Frogs. They quickly form a friendship (With Albus? You mean the kid with only one friend?) and reconnect later when the boys go off on their time-traveling adventure. Delphi is encouraging, she teaches them how to perform magic spells (as if they weren't students at a wizarding school), and even flirts with Albus by kissing his cheek. Why...she's as genuine as a slice of apple pie, I tell ya!

DELPHI: I was rubbish - and then something clicked. And it will for you too. Not that I'm a super witch or anything but - I think you're becoming quite some wizard, Albus Potter.

ALBUS: Then you should stick around, teach me more...

DELPHI: Of course I'm sticking around, we're friends, aren't we?

ALBUS: Yes. Yes. Definitely friends. Definitely.

To hammer this home, we see Delphi connect with Scorpius when he and Albus are on the outs. They share an emotional moment when she tells Scorpius that he really needs a friend. And that, wow, this is way more important than saving her cousin, Cedric.

SCORPIUS: Delphi, none of it worked, time-turning, we failed.

DELPHI: I know. Albus owled me. The history books changed but not enough - Cedric still died. In fact, failing the first task only made him more determined to win the second.

SCORPIUS: And Ron and Hermione have gone completely skewwhiff - and I still haven't figured out why.

DELPHI: And that's why Cedric has to wait. It's all become quite confused and you're entirely right to be keeping hold of the Time-Turner, Scorpius. But what I meant was - someone's got to do something about the two of you.

SCORPIUS: Oh.

DELPHI: You're best friends. Every owl he sends I can feel your absence. He's destroyed by it.

SCORPIUS: Sounds like he's found a shoulder to cry on. How many owls has he sent you now?

DELPHI smiles softly.

Sorry. That's - I didn't mean - I just - don't understand what's going on. I've tried to see him, talk to him, but every time I do he runs off.

DELPHI: You know, I didn't have a best friend when I was your age. I wanted one. Desperately. When I was younger I even invented one but -

SCORPIUS: I had one of those too. Called Flurry. We fell out over the correct rules of Gobstones.

DELPHI: Albus needs you, Scorpius. That's a wonderful thing.

SCORPIUS: He needs me to do what?

DELPHI: That's the thing, isn't it? About friendships. You don't know what he needs. You only know he needs it. Find him, Scorpius. You two - you belong together.

We witness this touching connection between the two of them, which is something I had enjoyed during the first read. When she was growing up, her only friend was imaginary. Hmm, same with Scorpius. She promotes what they have together and seems to be a sincerely sweet individual.

Then, after her reveal, the writers jackknife her to the other side of the spectrum, where she is using Crucio, the flippin' torture curse, on that same character in order to get Albus to agree to her terms. Then she's randomly killing Craig Whatever-his-name-is Jr. After that, Delphi claims that she is only using them... the excuse being some pulled-out-of-nowhere prophecy.

I mean... what? This is the exact opposite of what you've been developing in her! She's not the same character. Literally. This is Delphi we're talking about. The one who can be sweet and considerate, the one who was funny and taught them magic. Then you turn the page and she's a cold, brutal, merciless killer who is willing to destroy whatever and whomever to achieve her goals. If doesn't have any real reason to connect with them, none of her earlier actions make sense.

But wait...then you flip her back at the end when she wants to see Daddy Voldemort. Now, she is just a daughter wishing to see her father. Like, is she a psychopath? Or is she a charming, misunderstood girl with the wrong incentives who desperately wanted to see her dad? Pick one and stick with it, because the rest of us are utterly confused. You can't have both!

It's a fake leg!

We could not guess Delphi's secret identity, even if we had tried. Forcing us to never question her motives or consider her as a potential antagonist doesn't show creativity, it shows a lack of confidence in storytelling.

"Well...I don't want you to be able to solve the mystery," she could say.

"Okay. Then, back to the drawing board. Maybe, I don't know, try telling it better?"

The manipulation in this play is borderline hysterical.

I understand that part of the purpose in telling a mystery is to trick the reader, in a sense, but when the Scooby gang comes to unmask the character again and... oh, it was Mr. Thatcher the groundskeeper all along... yes, you want that puzzle to have been difficult for the reader to piece together. But it can't be so shocking that it could've never been suspected. On some level, you want that friend reading the book alongside you to say, "I knew it!"

If everyone is stunned silent, the only ones able to enjoy that moment are the writers. JKR and Co. wanted so badly to give us a shocking twist we could never see coming that they removed all possibility for the reader to arrive at that point themselves. They were tricking us with a classic trope, but the tactic was distorted to fit their aims and diminish their fears. Because no writer wants the mystery to be spoiled. And they showed us that fear in spades.

Keep Calm and Keep the Secrets.

We've all seen it done properly in the past. In Act One we learn that the killer had one leg. Act Two, the most likely suspect has two legs... Then, wait! They have a fake leg!

I get trying to pull off shock value. I'm all about shock value. But what we saw in Cursed Child just isn't good storytelling. There are ways you can shock your readers using misdirect without having to manipulate them until the last second. Buttress your narrative with an outline that develops the antagonist naturally, and audiences won't react unfavorably. Because, I'll tell you, we're not huge fans of Delphi. Not even in the "love to hate" them sense.

We're ambivalent...

...because we've been confunded.