After a fight between Aquaman and evil-Mera from last issue, Mera reveals on the last page that she was sent to kill Arthur!
This being the cliffhanger it’s hard to really elaborate more on it, but it leads the reader to believe that Mera was sent to Earth to kill Arthur, fell in love with him, didn’t do the job, and now her people are showing up to finish the job.
I got a dollar that says “Evil Mera” is Mera’s sister.