A meta example: how do you take a classic "monster" movie like The Invisible Man and make it an original take on the source material? The concept that Blumhouse goes with for this movie ended up being both brilliant and horrifying at the same time. Not only does it update the science-fiction elements of the story, but it also uses the source material as a way of telling a more modern tale that is relatable to a lot of people.
How did Cecilia know for a certainty that Adrian really WAS the one behind it all, and not Tom as he claimed? There are two clear signs: after Cecilia stabbed him with the pen, Adrian's suit continuously glitches during the hospital scene, while Tom is wearing a suit that isn't glitching (and, just as importantly, doesn't appear to be even slightly wet, despite Adrian being drenched at the hospital); and Tom manages to somehow beat Cecilia back to James' house, not just by a little bit, but by a wide enough margin that he's able to attack Sydney, and then nearly beat James (who had to get from his precinct to his house after receiving Cecilia's warning call) to death, long before Cecilia arrived to save them both. This second point would only work if Tom was actually already at James' house beforehand, likely waiting for the go-ahead from his brother to kill Sydney. Likewise, the extra time would have allowed Adrian to return to his house, stow the suit, seal himself in the basement, and tie himself up before the police arrived.
Another thing that's rather suspicious, is after Tom is killed, a police team enter Adrian's house, and Adrian is heard calling for help through the walls. Strange how nothing of the sort is heard earlier in the film, when Cecilia was snooping through.
Cecilia actually has one big clue: no matter how you spin the story, you can't escape the fact that Adrian was the one who build the suits, and would have had to tell the police about them. However, Cecilia knew there was at least one suit which was kept at his house and the police never recovered, the one she took and hid. And we see by James' reaction at the end that he never told the police about it. Cecilia knows about it, and Adrian doesn't know that she knows, so pretends he has told everything, and that's how she knows for sure he is lying and, after giving the chance to come clean at dinner, that he will keep doing so.
We never really hear about the specifics of Adrian’s abuse, since Cecilia leaves him at the beginning of the movie. Throughout the movie, however, Adrian uses a ton of abuse tactics that he likely used when they were together to drive her crazy, and are common tactics with abusers in general;
Hiding her important work for a job interview may seem quite petty, but it serves to make her seem forgetful or ditzy to the interviewer, and make it hard for her to earn her own income. After all, if she got a job, she wouldn’t be dependent on Adrian anymore.
Before doing anything excessively violent, Adrian does small things to make Cecilia look crazy or mentally unwell to James and Sydney, such as turning up the heat on the stove, or drugging her to make her seem impaired. Abusers tend to make their victims look crazy so that it's more difficult to believe when the seemingly well-adjusted abuser is accused of harming them.
Sydney thinks Cecilia hit her in the face, which is the breaking point for James as he tells Cecilia to leave. It’s not uncommon for abusers to act as if they were the ones being abused, to make the victim seem insane. Of course, Adrian can’t make himself seem like a victim, so he set up a scenario where it happened to someone else.
Adrian uses Cecilia's email to send a hurtful message to her sister, thereby cutting her off from outside support. Abusers always try to isolate their victims from close friends and family, often by stoking animosity between them.
When Tom tells Cecilia that Adrian needs her because she doesn’t need him, it sounds like he’s just saying how much of a control freak his brother is. But it’s more poignant than that; Adrian never loved Cecilia, and the only reason he does what he does is because he wants her purely out of spite. Adrian is a rich, handsome, and physically fit man, yet his horrible personality and sociopathy make him an emotional drain on both his brother and his ex-girlfriend. In other words, Adrian genuinely seems most happy when making others miserable. Meanwhile, Cecilia, at least at first, has her sister, James and Sydney as a support net, and has the wherewithal to get a job and start a career (before Adrian ruined it, at least), and despite her trauma, moves on from Adrian quite quickly after he’s dead. For all his power, Cecilia doesn’t need him, but he needs her so he has someone to abuse.
It could also be a Take That! to real life abusers, saying that abusive people are a drain on those they harm.
Tom is a foil to Cecilia; whereas Tom willingly obeys Adrian and acts as his pawn in hurting others, Cecilia refuses to submit to him and ends up his target. Fittingly, Tom’s story ends when he’s killed as a result of following his brother’s orders, whereas Cecilia is the one that kills Adrian for all he did.
People have begun to wonder, how did Adrian manage to wash the paint off so quickly after Cee found him in the house with it? While nothing in the movie explains it, it would be a bit of an oversight to make an invisibility suit which happens to pick up dust and lint and dirt as it goes. It's safe to assume it was designed to PREVENT stains sticking to it. It's possibly covered in something like Teflon, a non-sticky non-staining layer to avoid this very situation. This also explains why, even though Adrian is probably wearing the suit 24/7, he isn't leaving footprints anywhere. Thus, when he goes to the sink, all it takes is a very quick splash of water in the kitchen sink to wash off all of the paint right away.
When Cecilia shows up to the house to look for the suit, Zeus is still there. Why would a dog have been left in an empty house? Except, of course, Adrian never left...
Tom working with Adrian is actually foreshadowed from their names alone. In the original Invisible Man novel by HG Wells, titular invisible man Griffin enlists the help of a homeless man named Thomas Marvel, bullying him into helping with his schemes... and in this movie, 'Tom' and 'Griffin' were once again in on it together.
Some have argued that Emily's death would have been captured on a security camera, therefore proving that it was not done by Cecilia. But that actually plays into Adrian's plan, as he ends up framing his brother as being the one behind the manipulations and being the guy in the suit. If the police look at security footage and see a floating knife, then discover it was Tom in the suit, Adrian still gets off scot-free in the end.
It's possible this was the plan even if Cee went back to him, since Adrian seemed a little too well-prepared for his whole 'I was kidnapped' ploy... perhaps the plan was always to scapegoat Tom and possibly kill him in the process
The reason nobody was aware of Adrian's invisibility suit is that it was a prototype he was perfecting before revealing it to the world.
It's easy to glance over since the movie itself doesn't focus on it much, but when Cee gets the letter from Tom's law firm about the meeting, she questions how it got there since nobody is meant to know she's staying there... which is a very good point. It's only possible if someone like Adrian knew she was there, and could get it sent there to ensure she saw it.
While Cecilia killing Adrian at the end, and gaining her freedom in the process, is extremely cathartic, her manipulation of James in constructing her alibi has likely irreparably damaged their friendship, with his realization that the trauma Cecilia suffered drove her to behave as sociopathically as Adrian himself.
On the other hand, it really might not. First, James probably feels like he still owes Cecilia for not believing her and helping her before. Second, as noted above, the very fact Cecilia had access to the suit is a proof that Adrian was guilty and facing no consequences, and using his resources to force Cecilia back in his life by playing the victim. Lastly, Cecilia's behavior is nothing like Adrian's; Adrian abused Cecilia for a long time even before faking his death, and made lives' miserable for the sake of it, while she only reacted to her abuser who was about to get away with everything, two situations that don't really compare.
Though she is still walking out the door knowing full well she's getting away with murder, something that would rankle a cop, even if she had good reasons. He'll never be able to prove it, she knows that, he knows she knows that. She's put him in the position of having to choose between his duty to uphold the law and support his friend, then assured making the first choice is practically impossible. That's going to strain their friendship.
Given that Tom withdrew the Trust from Cecilia after she was committed, how likely is it that she's still cut off, even after Adrian was "found" alive? Tom mentions that he doesn't look forward to telling Sydney that the account that Cecilia set up for her college fund was now gone, and we receive no indication that the Trust was reinstated after Tom's death. Once news of Tom's actions broke, the will would likely have been invalidated, as, unless Adrian said otherwise, Tom's partners may have decided that it was created under duress (as per Adrian's story). Even worse? Adrian almost certainly didn't expect that Cecilia would try to kill him, so it's possible that there is no alternate will yet, or if there is, it probably wouldn't have been under the same terms as previously.
Though to be fair, Cecilia may not want the money anymore. It would certainly help with childcare (assuming she would keep the child abortion is always on the table), but considering it's her tormentor's money...
Usually people justify taking blood money by using it to benefit others like themselves.
On the other hand, it might actually turn well for Cecilia: Adrian is unlikely to have written a different will, since he was considered to be pretty safe, and the one he wrote could arguably considered written under duress, since Tom had no reason to force Adrian to write a will that benefitted Cecilia instead of himself. So, likely, the older version still applies, and since everything Cecilia went through happened before Adrian's death (and proven to be due to Tom's manipulation), it means they won't invalidate her. So Cecilia could just help Sydney through her studies, as she initially planned.
Crime scene photos were taken of Adrian's staged suicide. Meaning there were investigators on the scene. Which means actual police officers and investigators might have been in on Adrian's scheme. As rich as Adrian is, he may have paid a lot of them off to look the other way.
Any guesses on how Cecilia, who's been put through the wringer, physically and psychologically speaking, and has murdered two people now, plans to use that remaining invisibility suit?
Cecelia lampshades at one point that an incredibly handsome billionaire like Adrian could have any woman in the world but chooses to torment her instead. Elisabeth Moss is certainly not unattractive, but hardly the prototypical “Trophy Wife” you would expect for such an arrogant man. Instead Cecelia is shown to be intelligent and confident. Adrian enjoyed the challenge of having such a woman under his control.
