“Thawing Hearts” is episode four of season two of Harley Quinn.
Harley has melted a way through Mr Freeze’s ice wall with Firefly’s flamethrower they got in the previous episode, “Catwoman”. She decided to be artistic about it and, in the process, as Psycho points out, used up all the fuel.
Harley has been dreaming of this ever since Freeze froze her in “New Gotham”. Clayface tells her to look at her phone. Kite Man had proposed to Ivy, and they’ve just got a message; Ivy said yes. Harley says she and Ivy love weddings and making fun of the dumb couples. As they fight Freeze’s goons, Psycho points out that Ivy is the dumb couple. And Harley is told she needs to find a date. Post-Joker Harley doesn’t want to do serious, and taking someone to a wedding is serious. With the goons down, Mr Freeze comes out. And freezes them all.
Mr Freeze unfreezes them inside. He has no intention of killing them. He wants to cure his wife’s incredibly rare blood disease. It’s terminal. Which is sad, right? He’s been testing on the common snow rat, which shares 98% of its DNA with humans. The tests have been successful. Assuming ‘success’ is defined by ‘lots of dead rats.’ Mr Freeze plans to move onto humans. Harley suggests he gets it right on the rats first. No; Mr Freeze is 98% sure that the failures come from the 2% difference. He’s going to use Harley to test this theory. Because two of the others aren’t human, and Psycho barely qualifies.
Before Mr Freeze can inject Harley with something, she says she knows how to save Freeze’s wife’s life. Her friend the doctor is the smartest person she knows. No, not Dr Psycho; Ivy. Ivy will help Harley, so unfreeze her and let her send Ivy a message.
Harley was just buying time and plans to kidnap Freeze’s wife and threaten to kill her. This proves difficult, as they all end up frozen to chairs. Freeze’s frozen wife, Nora, is wheeled in. Harley takes office to her being frozen. Mr Freeze wants the food describing – eating it would kill him – and recounts how he and Nora met. Harley doesn’t think much of love. The others think Joker has ruined her.
At the mall, Kite Man has received a congratulatory message from his nemesis, the Condiment King. Kite Man explains that Condiment King is being sarcastic. Kite Man is also freaking out; he really wants to get the Old Gotham Corn Factory as their venue. It’s the venue. He’s dreamed of being married there. Ivy thinks they’ll be okay with a dance floor, alcohol and Kelly Clarkson’s greatest hits. At the venue, they aren’t the only people there. The Condiment King has arrived as well, and there’s only one free date on the calendar.
Harley decides that Nora doesn’t have a rare blood disease, and that Mr Freeze froze her because she was going to leave him. Harley thinks wrong, and they have to get Ivy involved. Whilst she and Kite Man were trying to get the venue. Harley does get a demonstration as to what non-Joker love involves.