I guess I will do what order I think the scenes will follow in 2x18.
1. Magnus and Luke off to the Seelie Court to tell the Queen about the soul sword… now she will probably say “it’s time for us to go against the clave” etc. etc. and offer Magnus and Luke to join her. Now we know Luke… he will say no to her offer, he doesn’t want a war. Magnus will say he has to think about it and somewhere a fucking flower comes in (this flower helped me pieced together that the alec and magnus scene comes after magnus comes back from the court)
2. Magnus will head back to the Institute, to tell Alec that he has to make tough choices and he needs a bit of time (this is not a break up no, remember Alec saying he will give Magnus space in 2x15? It’s basically like that) to make his choice… Alec will say i love you and along the lines I will give you the time you need to make this choice and off goes Magnus walking away.
3. Magnus staring outside of the window in his loft, hes thinking here, he’s deep in thought, and that will cue the flashbacks to 2x07 and maybe the s1 flashback. He will think about how they fell in love, their first time, and how Alec asked for him to show his cat eyes to him (I am sure that’s how that flashback scene will go) and they make love then cuts to the morning after scene, where they are happy and in bliss, then maybe cut to when Magnus realize he was falling in love with Alec (s1 flashback) and how they said they were all for effort and if he sides with the Seelie Queen, he’d hurt Alec, betray him, and she really wants all of the Shadowhunters dead… he couldn’t side with someone who basically wants to kill the man he loves and it wouldn’t be good for his people either.
4. The stills, I think Alec will either come over to apologize or he came over to fucking fight for the man he loves, he will probably snap Magnus out of his daze or Magnus already made up his mind by the time he got there, who knows. What happens here I have no clue…. Alec might get the call about what happened to Max and he and Magnus rush off to the Institute. With or without Alec finding out who Magnus chooses to side with…. we won’t know.
5. The hand holding scene from the sdcc trailer. In that scene, Alec looks hurt, upset, and Magnus is there comforting him, I don’t think Magnus wouldn’t be there if a. he decided to side with the queen and b. if they broke up or whatever. (also important here Magnus isn’t wearing the coat when he walks off from Alec, now that would be a fucked up thing if Magnus walked off when Alec needs him) now if Alec doesn’t know what Magnus’ answer is I am sure he will ask here, because he wants to know…. Magnus will probably say i choose you…. (idk why I get the feeling he would say that, he can’t trust the queen, he can’t trust the clave, but he CAN trust alec).
And what happens after this, I don’t know I will probably turn into that snow man from Frozen after this ep.