Story is actually going back to forth, from past to present in terms of flashbacks. Zeke when came to know about Eren as his step-brothers, he said he would come back to get him or so along the lines. When Zeke and Reiner returned, Zeke incorporated Yelena in his plans and got her to be purposely captured by Survey Corps. That became the connection betweenn him and Eren. Since some of Marley men are there after being captured, they have started using Marley's Knowledge which is being directed by Yelena under Zeke's plan which happened between when Eren being in the age group 16-19. Thus the advancement in their resources. Zeke further incorporated other countries who may be beneficial to Paradise Island which led to contact of the lady who wants Mikasa( Reiner must have told Zeke roughly about Mikasa and while Zeke and that lady had a talk, they must have figured about Mikasa). Further Zeke wants to transfer his powers to Historia instead to the one of Marley because of the pure royal blood and powers that come along with it. Eren figured Historia would be used like this in earlier chapters which is why he was so angry with Hange. The military police members were talking about Historia's pregnancy and the father and whether they should trust the captured Marley or not. Further they concerned about the after effect of Eren's action and thereby the bitter reaction from their side. Marley now know that Zeke planned fake death and is planning to attack and saving Gabi and Falco as per Reiner's statements. The major concern of the story line is stop Marley from making Paradise Island look like a devil's island and destroy it completely while taking all the 9 titans back and making itself the strongest country as in the past when Ymir was around.this is my guess. Story in being from multiple viewpoints and step by step final plan development is taking place, forming alliances, building equipments and so on.
I hope you understood it.Sorry for the long post I couldn't shorten it.
Thanku for the explanation but i still dont get it.
Arigatouヾ(❀╹◡╹)ﾉ~
Hahahaha...it happens.
What the hell is happening? I cant seem to follow the story line