"Chemistry", huh? This time Dexter compares his new affection to other women he's been with throughout the series: Rita, Lila and Lumen, and comes to a conclusion that Hannah might be the one he could actually fall in love with. Isaak Sirko again appeared in just a few short scenes, which is a bummer. And last but not least, Debra got bloodthirsty.
Debra's date with Sal Price went well, they had connection and even kissed. The whole evening they talked about Hannah, though, and Debra was determined to nail her and put her behind bars. Sal says he suspects Hannah poisoned her husband and so his body can be exhumed and checked for traces of aconite.
Dexter drives Hannah back home after their crazy murder-date. They agree to stop seeing each other, because it'd wouldn't end good. When Hannah leaves, Sal, who happened to watch her house at the time, approaches Dexter and accuses him of sabotaging the blood report on purpose. He threatens to write about this in his book, so Dexter offers him to go on record with Wayne Randall's last words instead. In the end they agree to meet at Dexter's house to talk about it.
Miami Metro staff discover that Isaak's blood from the evidence room is missing. Dexter and others go to the crime seen to get the leftovers of blood there, but the sewage was ruined, presumably by Koshka's, so nothing could be retrieved. Dex tells Debra that he'll manage Isaak his way, she yells at him and says he must stay away from the guy and that she'll arrange police following Sirko wherever he goes until his visa expires.
Batista gets the list of visitors of the evidence room, and asks Quinn what he was doing there. Quinn lies very persuasively, so Batista gets off his back. Later Quinn gives Batista a check for ten grand for that restaurant he wanted to open.
Sal comes to Hannah and insists on an interview, when he brings Dexter up, she agrees. Dexter comes to warn her about his talk with Price and she tells him about her conversation with that nosy writer. Dex says he'll handle the guy.
Debra gets permission from Hannah's sister-in-law to exhume the body of the deceased husband, but there were no tissue on the corpse.
Isaak shares a chip with Dexter and tells him that he now has cold head and he won't be so easy to trap any more. To destabilize him Dexter tells in detail how he killed Viktor, but Isaak just leaves saying "You'll regret sharing this with me".
Dexter can't just kill Price for nothing, and it would be too suspicious if he did. So he tries to find some dirt on the guy and comes across with one murder Sal wrote about, which was never solved. Dex suspects Price was the murderer. He then breaks into Sal's apartment, steals his toothbrush and some used dental floss, and erases the book and materials about Hannah from Sal's computer.
Sal interviews Hannah and she tells him a compelling story about how Wayne practically made her kill that woman that the police recently dug up.
Quinn is reunited with Nadia, but George is not willing to let her go and give her passport. Well, it was really naive to believe him in the first place, wasn't it.
Price comes to Dexter and instead of hearing the story about Wayne, he hears something different. Dexter says he has proof that Price himself is a killer. They argue and the Price dies from a heart attack.
Maria finally discovers that Dexter Morgan has a boat (that's in relation to the Bay Harbor Butcher case).
Hannah is interrogated by Debra, but it turns out she's very good at lying. Dexter pays her a visit afterwards, and they come to a conclusion that they were looking out for each other. They naturally have sex after this discovery. As Dexter reflects lying next to sleeping Hannah in her bed, his cell phone rings. Debra tells him they couldn't find any trace of poison in Sal's body, so she basically asks him to kill the girl.