In 2004, Ashton Kutcher was in a movie with the tagline: You cannot change who people are without destroying who they were. That movie was called Butterfly Effect.

The film borrowed its title from the scope of time travel the studio was attempting to present to the audience. In the briefest sense, the "butterfly effect" can be defined as a small cause creating large effects.

Again...Cause and Effect.

Causality.

The butterfly effect is actually a mathematical concept that started out as a form of weather prediction. Or, as Ian Malcolm eloquently puts it in Jurrasic Park, "A butterfly flaps its wings in Beijing and the weather changes in New York." Sci-Fi storytellers have adopted this concept of forecasting future weather patterns to explain the causality in Dynamic Timeline time travel.

Allow me to break it down:

Fixed Timeline (presented in Prisoner of Azkaban): You cannot change history because the past always included you and your attempts to alter it, with the likelihood of creating time loops.

Dynamic Timeline (presented in Cursed Child): You can change history, leading to vastly unexpected results and potential paradoxes, like nullifying the birth of your best friend by unintentionally killing his father. Or causing Ron's hair to part differently. Some would say, "super-aggressively" .

(*wonders if he should even describe the finer levels of exasperated face twitching going on at the moment*)

Why their attempt doesn't make sense:

1. Delphi wants to go back with them. Albus and Scorpius say no (because they're boys and we all know that boys are in control - sarcasmmmm). Delphi wants to know how they will be able to work the Time-Turner without her. They respond by saying that she already taught them. Mmm... How does she know how to use it? It's been in their possession since it was taken from the Ministry. Pretty sure there weren't any other Time-Turners chilling out in the world when Delphi grew up, where she could've attained some sort of proficiency with them. So... what makes her the expert?

2. Delphi gives the boys Durmstrang robes so they can go undetected. Uhm... where did the Durmstrang robes just... come from? Did they sprout from her arms? Why aren't Albus and Scorpius like, "Hey... that's weird. Where'd you snag those bad boys?"Also, there should've been three robes, if my math is correct. Because she had only just decided, right then, not to go along for the ride. Like, I get that the robes are a minor detail, but it shows an absurd level of negligence. And for what? For the purpose of filling in a tiny plot hole that they probably noticed right before the book went to print?

Ooh, guys... Uh... wouldn't Hermione pick up on the fact that they weren't Hogwarts students when they sat next to her? Same year in school, and all. What should we do?

Oh, no need to worry. Jack will sort it out. He's the best writer on the planet. Didn't you know?

So dummm. You want us to believe that Delphi just... had those school uniforms ready? In their sizes? Circe 1994 / 1995? Mm. Eh-heh.

3. They plan to disarm Cedric during the task so he loses and has a worse chance at winning the tournament. Thus saving his life. Okay then, answer me this: If they are going into the past with the specific purpose of saving Cedric, why... exactly... would their first idea be to yank his wand away? Like... when he's facing a dragon alone? I guess it's better to have him die by the scalding hell of dragon fire... than by... Voldemort...? That makes sense. Yep.

*obligatory eye roll*

4. During the Triwizard Tournament, Bagman announces that Cedric was disarmed. How was that allowed to just happen? I mean, such a comment would indicate that someone else had done the disarming. Everyone in attendance would be alerted. Then what? Cause and Effect. This would have been an outrageous controversy and would likely derail the entire tournament. Didn't think of that little gem, Jack?

Oh. Hmm.

5. It seems to me that the champions of the tournament would be protected from the meddling of rival schools. Their whole plan, and the events that transpired because of their plan (which means THE ENTIRE PLAY) hinges on this one idea. But, no. Nothing happens. Really? There were all these safeguards on the cup at the beginning of the book, but... they don't protect the actual players of the tournament from outside interference? It would be pretty easy for Dumbledore to prevent disarming spells from being used to influence the outcome.

Lack-of-LO-GIC!

6. If you happened to have forgotten (and this is a constant source of frustration for me as they continue to travel back in time), there are new rules for this Time-Turner. Users can only go back for five minutes. Yes, five! Upping the stakes, are we? Or just looking for a way to wrap up the time travel quickly because you're trying to cram a novel onto a stage meant for small stories. Five minutes, and yet they somehow manage to stop time traveling at the exact moment that Cedric Diggory is facing the first task.

*slow blink*

There are so many holes in their logic, it's just dumping water through a strainer at this point.

It. Don't. Hold. Water. Yo.

Laws of Time Travel:

1. AS LONG AS NOTHING AT ALL IS CHANGED, THE PRESENT WILL REMAIN INTACT UNTIL THE TRAVELERS RETURN TO THE PRESENT. THEY WILL BE SLIGHTLY OLDER THAN BEFORE.

2. SOMETHING IS ALWAYS CHANGED IN THIS VARIANT OF TIME TRAVEL.

3. CHANGING THE PAST CAUSES A DIVERGENCE IN THE TIMELINE - AN ALTERNATE UNIVERSE / FUTURE OVERWRITES THE ORIGINAL.

4. EVERYONE LIVING IN "ALT-UNIVERSE 1" LIVED THE EXACT SAME AS BEFORE UP UNTIL THE MOMENT OF THE DIVERGENCE. THAT MEANS, THE VERY INSTANT CEDRIC WAS DISARMED, EVERY SINGLE CHARACTER CARRIED ON DEVELOPING INTO COMPLETELY DIFFERENT PEOPLE, WITH VASTLY CONTRASTING HISTORIES, ALL AFFECTING ONE ANOTHER TOWARD NEW DESTINATIONS.

Or, at least, that's what should've happened. Correction... none of this should've happened, but you know what I mean.

The CAUSE of the divergence:

1. Cedric was disarmed during the first task.

2. Hermione was suspicious of two Durmstrang boys.

3. Hermione didn't go to ball with Viktor Krum.

The EFFECT of the divergence:

1. Ron no longer knows jokes. Ron no longer works at Weasleys Wizard Wheezes. Ron parts his hair severely (look out! dang!). Ron dresses seriously. Ron now thinks that a set of quills is a good gift for a teenager. Ron is apparently far less creepy (so, y'know, points for that). Ron married Padma Patil (rofl). They have a son, Panju, who is cousin to Albus.

2. Ron and Hermione were never married. Meaning that Rose was never born. Oh, and the same goes for her brother, Whatever-his-name-is (because what's the point in remembering his name when he disappeared in this story faster than a cloaked Harry in the restricted section of the library).

3. Hermione teaches Defense Against the Dark Arts at Hogwarts. She has become a very bitter and angry person, nearly unrecognizable.

4. Albus won a bet with Panju that he could convince the Sorting Hat to place him into Gryffindor. It does. Albus hates his own house (because people stay the same in both universes regardless of what actually happens to them).

5. The fighting between Albus and Harry hasn't changed one iota.

Why the universe doesn't make sense:

1. You're saying that practically everyone and everything, including all history in the wizarding world, is the same beyond Ron and Hermione? Bwahahahaaaa! So, Harry is unchanged. We even see an entire scene from his point of view with Dumbledore. Oh, and that one with Bane still happened. Yep, he's exactly the same. Don't start questioning things, folks!

2. Harry's little convo with Albus. Just... what? Everything about their situation is identical to what happened before. It defies all logic.

ALBUS: When we returned after failing to fix the first task, I was suddenly in Gryffindor House. Nothing was better between us then either - so - the fact that I'm in Slytherin - that's not the reason for our problems. It's not just about that.

No, being in Slytherin wasn't the source of your problems. It was because you and Rose went searching the cabins and you befriended Scorpius Malfoy. Changing the past and overwriting Rose with Panju would COMPLETELY change that scenario and likely prevent your friendship with Scorpius, and therefore, those pesky daddy issues.

BUT THAT WOULD BE AN ENORMOUS PARADOX BECAUSE THE TWO OF YOU TIME TRAVELED TOGETHER.

(*brain explodes*)

3. Everything about Alt-Ron.

It's a waste of my time. I'm not even typing it out.

4. The love story between Hermione and Ron. Something as small as a school dance would not have thrown this off. Even basic fans know these characters enough to never consider writing that garbage. Especially because rejecting Viktor Krum would have allowed Hermione to go to the Yule Ball with Ron. He had asked her in his silly way, but she was already committed to Krum. And, apparently, Ron's date to the ball defined his entire future with women... which is totally logical... so, if anything, they'd just hook up earlier. At the VERY least, Hermione would've gone to the ball with Harry, and the Golden Trio would have been strengthened because of their friendship. You just know Ron would've gotten a sweet dance out of it. Maybe even a kiss at the end of the night. So don't you start bringing this weak ass shit to my table, bruv. Romione, bitch.

5. Everything with Alt-Hermione is just wrong. She wouldn't become some angry shrew. She calls her students a "disappointing bunch" for not knowing anything about casting a Patronus. Uhm... Harry was taught third year by Professor Lupin because of his issue with dementors. You're just trying to remind the reader because of the scene with Scorpius and Snape later. What great writers you are! Really, there isn't a need. Y'all, we know what a Patronus is, kay? And this lesson ain't even legit because fourth year canon curriculum never covered the Patronus Charm. You would be aware of this fact had you, I dunno, READ! THE! BOOKS!

6. Ron and Padma... C'mon. haha. Could you point out a single scene from OS-Canon where they exhibited even a smidge of chemistry? Kid, enough with this.

7. Let's talk about Panju. Panju would have been Albus's best friend growing up. They were cousins, both attending Hogwarts at the same time, likely in the same house. We know that the division between Albus and Rose was due to house placement. So, why don't we hear anything about Panju when Albus returns to find himself in an alternate future, more than likely sleeping in the bed directly beside his *new* cousin? They would have been chatting it up the whole time!

And honestly, this would have been good for the plot. Let Albus and Panju bond. Because then, Albus would have to accept that, while they deleted Rose and that other kid we don't talk about (Hugh?), returning everything back to the way it was before the divergence would erase Panju! His Alt-cousin would've never been born, which would make their decision to go back in time again vastly more difficult. Because in EITHER scenario, someone's life had to be snuffed. The weight of responsibility on them would be greater, and... could you imagine...? Character development would commence!!! WHAAAA????

8. Delphi shows up to the school and is fully aware of their plan and how it did or didn't work. MERLIN'S SHIRTSLEEVE! How is Alt-Delphi at all aware of this? She acts as if she went back as well, and has the knowledge of both universes. No. Nope. She's not all-knowing, so just stop. This version of Delphi grew up in a world where Cedric was always disarmed in the first task. Meaning that she wouldn't have ever suggested that Albus and Scorpius go back to cause that.

It's SO confusing. A similar thing happened with Hermione.

9. Hermione's introduction doesn't make a lick of sense.

ALBUS enters the classroom - slightly unsure.

HERMIONE: Ah yes. Our train absconder. Finally joining us.

Train absconder? WHAT??? He didn't abscond from the train in your universe, dood!! He did it in the Origin Universe... in order to change the past. Remember? Here, in THIS universe, where the past was already changed, Albus and Scorpius conceivably arrived at school like normal. Albus didn't "abscond" from anything in this reality. Remember... Alt-Universe 1, he grew up in a world where Ron and Padma were always together. Just... I can't.

10. Last question. Why didn't Albus just walk right up to Alt-Hermione and ask for help by confessing that he was one of those Durmstrang boys from the first task of the Triwizard Tournament, and that this reality was a result of them meddling with a Time-Turner? That could've avoided a lot of really unnesesary filler in this gawdawful plot and Hermione would have made sure that everything was set right, since she spent more time with that particular magical device than anyone.

I have more to get into when it comes to Hermione and Albus, but it starts to define another variant of time travel that the Cursed Trio started gradually leaning into.

*exasperated breath*

I know. Could this play get any more convoluted?

The answer is: hahahhaaa, yes.