Well, since there is a spoiler warning in the thread title, here goes:
Ray Palmer, in the afterglow of sex, is talking to his wife, and she asks whether they discovered who wrote that note Jack Drake was discovered with. But Batman did not release that note to the public, and Ray Palmer knows this (gasp!). He verbally confronts his wife, and she admits that she did it all! She used Ray's shrinky stuff in the closet to try to scare Sue Dibny, but because she didn't know how it all worked, accidently went through the phone, not into the air, but into Sue's brain. Not knowing what was what, she grew slightly and this killed Sue. Then she used her portable villain torch to, well, torch Sue. The rest was all misdirection. She hired the calculator to sent a cheap villain after Jack Drake, but thought that Jack Drake would handle him with the gun.
In short, she was crazy, crazy, crazy. Her motive, to scare the heroes and win back Ray's heart in so doing. Now she is incarcerated in that gentle place of healing, Arkham Asylum (which has such a good track record I am hard-pressed to think of ONE person it has cured (maybe Harvey Dent?)).

Well at least she got some good ex-husband sex out of it.
Ray Palmer, after turning his ex-wife in, feels so "small" that he shrinks away and no one has heard from him.
Flash invites Ollie to go out with him and Clark occasionally for coffee and such.
Ollie tells Ralph to try talking to Sue. So we have this cute thing at the end where Ralph is doing just that.
Oh, and apparently Lois Lane is a terrible cook.
Finally, Flash has so far not told Batman that the other leagers took away his memories.