“Pick Your Poison” is episode seven of season three of Batwoman and the midseason finale.
Marquis is meeting with Ryan in a garage. It’s a trick, though; Ryan has lured him here so he can be sedated and carted off to be frozen. With that done, Jada asks what favour it is that Ryan needs.
Sophie wakes in Renee’s bed, alone. There’s a note. Sophie may be having regrets. She checks her phone, then heads in to Wayne. Meeting Luke, his arm in a sling thanks to Poison Mary in the previous episode, “How Does Your Garden Grow?”. Sophie asks if Mary really is Poison Ivy. It depends. During the night, she’s fine. During the day, not so much. Sophie asks if there’s a cure. Ryan returns and says there will be. Jeturian is working on it. Sophie says Jada doesn’t do altruism, so what’s in it for her?
Marquis is being prepped to be frozen. They’re taking it slow, so Jada asks about the other thing. The doctor says they’ve not seen anything like it since Swamp Thing. But they’re synthesising a cure now.
Ryan, Luke and Sophie are heading into the Batcave; Ryan has filled them in on Marquis. Luke asks if Jada will actually deliver. Ryan says there’s no choice; the way the infection is doubling, this may be the last night Mary is Mary. Luke has got no hits on Mary so far. Then the console goes. It’s Alice; she’s breached her perimeter. Sophie is asked where her roommate said she was going. Sophie didn’t get home last night. Ryan suddenly wonders if Mary is with Alice. She wonders correctly.
Mary wakes and asks Alice why they’re in a motorhome. Because they wrecked their sports car fleeing the GCPD. Mary asks what Alice did. It’s not what Alice did. If Mary doesn’t remember, that’s probably for the best. Mary looks for her phone. Alice says Mary threw it into the river. And explains what else she did. Mary is worried she’s going to be a fugitive for the rest of her life. No, just until she learns to control her powers. Alice will keep her safe until then. And Alice would like a blood transfusion to get rid of the nanobots. Who does Mary trust right now? Her friends, who will lock her away? Or Alice? It seems Alice.
Ryan and Sophie are in the Batmobile when Luke starts getting multiple Alices. They pull one over. Alice wrote on the boot in her blood. And made it clear Mary is with her.
Mary has got supplies, though not blood, from a hospital. Alice isn’t picky about a donor. Mary says she has to be; she’s O negative and needs the same. They try to get people’s blood in a bar and nearly get thrown out. Until Mary uses a new power. Poison Ivy’s mind control pheromones. She tries it again. They get free shots.
Luke’s plan for finding the real Alice is to wait until the blood dries and the nanobots die. Not a great plan. Sophie says that if Mary goes full blown Poison Ivy, extreme measures will be used against her. Luke calls; the cure is ready.
Marquis is being frozen and he’s crying. A trick to lure his mother over. He gets away; Ryan and Sophie find Jada on the floor. She says Marquis has gone looking for Ryan. He’s found Luke. Luke calls for security and Marquis kills the guard with a pen. Luke tries to fight, but he’s still in bad shape thanks to Mary.
Mary and Alice are using Mary’s new power to get people to give them blood samples. You can guess that, when Marquis left, he took the cure as well. He’s also laughing a lot and talking about putting a smile on people’s faces. That is not a reassuring sign. Things are going very badly wrong.