Callie and Arizona's custody battle may be over in the courtroom but the tension sees no end in "Grey's Anatomy" season 12, episode 23, titled "At Last."

In the previous episode of the hit ABC drama, fans watched Penny mess it up for Callie when she gave the court an impression that she did not know Sofia that well.

Arizona ultimately won custody of the little girl, which Callie appears to blame on Penny. This jeopardizes their prior plans to move to Seattle.

It remains to be seen if they will go through with it. What's sure is that the outcome of the legal battle will strain Penny and Callie's relationship in "Grey's Anatomy" season 12, episode 23 and in future episodes.

Despite what the legal battle made out of Callie, Penny and Arizona, Kevin McKidd, who plays Owen in the series, promised to TV Line that it will end with "a really beautiful payoff" in the season 12 finale. It should also give way to Sara Ramirez's character Callie being written off from the show.

The penultimate episode of "Grey's Anatomy" season 12 also introduces a lot of developments in the relationships inside Grey Sloan Memorial Hospital. The promo for episode 23 teases that there will be one hook-up and two proposals.

If the promo is any indicator, the hook-up will happen between Owen and Amelia, who were seen in bed together. This could be what ABC meant when they teased in the synopsis that the two will "take their relationship to the next level."

This could also mean that Owen will decide to pop the question possibly after the intimate moment. The promo, however, teases this hook-up will be "shocking" so it might happen between two people that fans never thought will ever get in bed together.

Meanwhile, Stephanie and Kyle seem to have forgotten about their breakup as they were seen kissing in the "Grey's Anatomy" season 12 promo. It remains to be seen if they fall on the proposal or the hook-up category.

Lastly, Alex will realize important things about his relationship with Jo in this episode, pushing him to do something yet to be revealed. But based on the promo photos and the trailer, Meredith will urge him not to do whatever he plans on doing.

"Grey's Anatomy" season 12, episode 23, "At Last" will air May 12 at 8 p.m. ET on ABC.