Like it's an entire thing, he goes to the State Records place and gets denied access to it since it's military above his paygrade info, then he goes to Maes where he says he doesn't know much about him and mentions in passing that his wife was dead-the first Ed hears of this.
As Tananari mentioned there's an ever growing sense of unease going on, like Tucker was, or at least
acted like, a regular family man working on research and we se things starting to pile up on him and being pushed by desperation.
Tucker acts like this jovial regular familyman if beleagured, not this ominous sociopath focused only on research-he doesn't reveal that until at the very end.
Also this is the first episode to introduce Scar, who we first see trying to force his way into the Records in rags basically and bolts after Ed accidently tears his sleeve off and he bolts and hides in an alley somewhere.
He isn't this clear Crusader with his mind set and on his journey, he's just a confused refugee trying to understand why his brother gave him his ability.
This ties into the changes a lot, Scar doesn't meet and kill Brigadier General Basque Grand in the 2003 anime, Grand actually shows up personally to put serious pressure on Tucker the 2nd night before the Assessment, and the same night he transmutes Nina.
Ed and Al are actually shoved off the property and forbidden to go in since Ed started beef with Grand and got a serious gut-punch out of it-a literal one, not the type that comes after this.
So he and Al sneak onto the property and try to find Nina, going down into the freaky animal basement they hadn't been to before.
We then get the interaction with Tucker and Ed, Ed putting it together, nearly beating Tucker to death etc.
Even
this varies heavily from Brotherhood, despite them having the same actions.
Ed doesn't put it together on the spot like in Brotherhood, in 2003 he's been doing an investigation like I mentioned for the last half of the episode and Ed-and the viewers-have this growing sense of unease-for example as Ed finds Nina and Tucker we ourselves have come to this conclusion which culminates with Tucker even mentioning "the other one was too old to adfapt that's why it didn't work".
Again mirroring the viewer-or intending to you know what I mean-we are treated to Ed slumping in defeat and sorrow coming to terms with the truth, with Nina nuzzling against him while repeating "Edward my friend" as this sinks in and isn't a one-click-and-done type thing, he doesn't gather his energy until this like 30 second or whatever sequence here.
Oh right he gathers his energy from anger as Nina says "Edward why does it hurt here".
Additionally it isn't til Ed outright states/accuses him of transmuting his wife that for the first time Tucker drops his act and we see him as the unhinged heartless bastard.
When Al asked why he did it, since the Assesment was supposed to be about maintaing his style of lifem so what point is there without his family, Tuckers response is "That's the funny part, I didn't
have a reason."
He says that he was screwed either way, but at least with the route he went he'd at least progress his knowledge.
Ed begins beating him and it isn't Al that first stops him, it's Nina tugging at him growling.
Ed straight up starts to try to separate Nina and Alexander from each other until Tucker points out how well that worked out for his Mom-also Ed's been having PTSD flashbacks since he saw the body of a woman killed by a serial killer.
He and Al are helpless to do anything, and at this point Brigadier General Basque Grand brings his butterfly effect of not dying and stomps in accusing Ed of assaulting military personnel and ends up with Tucker being arrested and he and Nina are loaded up in a transport.
Ed decides to hell with it-he's just realized that Grand had known the entire time and knocks the transport over, allowing Nina to escape.
Nina runs in fear and hides in an alleyway-the one with Scar.
We see Scar touching her and Scar doesn't know why, but he knows that she's a chimera in tortured pain.
We see him affirm his mission of hunting down alchemists as he puts his hand on Nina's head and explains he'll put her out of her misery.
As he glows we cut to Ed trying to find Nina and looking around and looking down the alley Nina and Scar were in and has to do a double take to figure out what he's seeing.
So yeah yknow how Brotherhood shows him killing people by running up and making the heads spurt blood but look fine after?
This is our first introduction to him and his abilities.
Yeah.
The episode ends with Ed's tears falling on the ground and panning up to show the rain falling as he sobs.