Dean Munsch gathers everyone to complain about the quality of the hospital's blood supply, pointing out that it's just the victims' blood mopped up and put back in bags (per Chanel #3). Chanel comes up with the idea for a blood drive.
Nurse Hoffel, via a voiceover, reveals that she is Agatha Beans sister. She has a vendetta against the Chanels for having killed her sister and gotten away with it. She comes up with a contest for whoever wins the blood drive to get an all expense paid trip to Blood Island, an extremely dangerous and deadly island in the south China Sea. She intends for the Chanels to win so they can die without her having to get blood on her hands.
Dr. Holt's murderer hand begins acting up, but Chane ignores it.
Zayday, while drawing blood from #5, comes up with the idea to eliminate possibilities for the 1985 baby by figuring out the parents' blood types and matching them to the blood types of various people in the hospital.
Chanel wants to win the contest to take Brock Holt on a romantic getaway to the island with her. Munsch insinuates that Chanel has STDs, making Brock nervous. Before getting intimate with Chanel, he insists that she get screened for every imaginable STD. Munsch switches out Chanel's blood so the results come back saying that she has every single STD possible. Brock refuses to have sex with Chanel and Munsch removes Chanel's collected blood bags from her blood bag count in the contest, much to Chanel's aggravation.
Hester, bored with nothing to do in the Chanels' apartment, demands that Chanel come up with something for her to do or Hester will begin killing people out of sheer boredom. Chanel confesses to Munsch that she's been harboring Hester and asks Munsch to given Hester something to do. Munsch agrees and gives Hester a patient to work on -- a young man with fangs, an aversion to sunlight, and an addiction to blood who believes he is a real vampire -- allowing Hester to remain free so long as she cures him.
Chanel attempts to catch back up in the blood contest by stealing blood bags from an outside collection truck. However, when she goes to stash the stolen blood, she notices her old bags were stolen. Unbeknownst to her, they were stolen by Hester. Hester figures out that her patient has an incurable disease, but his addiction to blood is just in his head. In order to cure him of his blood addiction, she force feeds him blood, intending to make him ingest so much that he gets sick of it and never wants it again -- hence Hester stealing Chanel's blood bags. Chanel discovers it and Munsch forbids Hester from continuing to steal the blood for the patient's aversion therapy.
Meanwhile, Zayday attempts to collect blood from Jane, the hospital victim's widow from 1985. Jane refuses. At the hospital, Chamberlain asks Zayday why she's acting strangely around him. He points out that Zayday think he's the Green Meanie/the 1985 baby and that he knows what Zayday is planning with finding out the parents' blood types because he was thinking the same thing. He tries to work with her to rule himself out as the killer, but Zayday refuses. Chamberlain goes on his own to collect a sample of Jane's saliva to figure out her blood type. He proves to Zayday that his blood type rules him out as the 1985 baby and they embrace. Zayday realizes that the baby's blood has to be O+.
When #5 is bled almost dry by Chanel in Chanel's effort to win the blood drive contest, Chanel switches gears and demands that Chanel #9 donate blood instead. #9 has a fear of needles and refuses. Chanel eventually manages to convince #9 to donate blood and takes her to a remote section of the hospital in order to strap her down and collect her blood. Chanel is distracted by Dr. Holt and leaves #9 alone. She tries to convince him that her blood results were faked.
Hester takes Chanel's blood, which Chamberlain was going to dump in the swamp because of its taintedness, to finish her aversion therapy cure with her patient. Munsch and Chanel catch her and she reveals that she tested the blood before giving it to the patient and it was clean -- proving that Munsch fakes Chanel's blood test results.
While Chanel is distracted, the Green Meanie arrives to kill #9. Hoffel interrupts, undeterred, and asks the Green Meanie to reveal himself. Unmasked, the killer is Cassidy Cascade. Hoffel and Cassidy agree to work together. Cassidy assumes that Hoffel is the other Green Meanie killer, noting that he didn't kill all the victims, but Hoffel mentions she hadn't killed anyone yet. In addition to Hoffel and Cassidy, there's a third Green Meanie killer. Hoffel and Cassidy kill #9 together by hooking her up to multiple blood bags and draining all her blood.
Chanel, Brock, and Munsch discover #9's blood drained dead body. With the blood from #9, Chanel wins the blood drive contest, much to Hoffel's happiness. Unfortunately for Hoffel, Chanel refuses the trip to Blood Island when she learns that she's have to fly business select, claiming she only flies charter. She demands the cash equivalency option, enraging Hoffel who can't afford it.
Cassidy swaps the blood tags, framing Dr. Holt as the one who is O+ instead of him and as the 1985 baby/probable Green Meanie killer. Munsch, Zayday, and Chamberlain confront Holt, who flies into a murderous rage at being accused.