The penultimate episode of Orphan Black aired tonight and we discovered not only who the Castor mole is, but some very, very valuable information about the original.

The First, the beast, the curse

Sarah, Mrs. S and Felix arrive in London and head to Mrs. S’ old neighborhood, from before she took in Felix and Sarah. They meet Terry, an old friend that helped connect her with Felix and Sarah, and he provides them with a gun. Mrs. S plans on killing the Castor original.

Terry says that the number from the riddle corresponds to old prisoner numbers from way back when, and it should/might be connected to a prisoner from back then, so he leaves to check it out. He does find something and calls Mrs. S to go to his place to talk but when he arrives there he finds Ferdinand and his lackey waiting for him. Ferdinand says Terry was supposed to call if Mrs. S ever came back to London and Terry starts making excuses, but then his lackey starts to strangle him with an electrical chord and beating him, ending with his interrogation.

Mrs. S, Felix and Sarah get to Terry’s place and find him an inch away from death, but before he dies he tells Mrs. S something that makes her want to turn around and go back home. She tells Sarah and Felix to go to the bar but Sarah doesn’t want to go back home, and she finds a cell phone on the floor on their way out.

Sarah calls the last number that called the cell phone and tells them she’s Mrs. S and she’ll meet them in the square a few blocks away. They get picked up by someone who takes them to the guy she called, and they find out he’s the guy who helped Mrs. S shuffle Sarah from place to place way back when. They ask him what he told Terry, and the guy gives them a piece of paper naming the prisoner attached to the number in the riddle: Kendall Malone, who was out on parole in 2007.

The paper has a recent address, so they ask Mrs. S’ friend to take them there. When they get there Sarah goes in to the apartment while Felix stands guard outside, and Ferdinand kills the friend that took them there. Sarah finds Kendall Malone, only it’s a woman! And when Mrs. S shows up to the apartment she tells Sarah to put the gun down because Kendall Malone is Mrs. S’ mother. Dun dun dunnnn.

Kendall explains that Duncan came ’round the prison way back when testing inmates, men and women, to look for a viable donor. He says he found the male donor – in her. She absorbed a twin when she was in the womb so she has two cell lines, whatever that means, and so she’s the Castor original – and the Leda one.

Don’t threaten babies

Gemma is training for a karate competition and Helena helps her prepare — Helena really is a family woman. Meanwhile, Donnie is fine, guys! He woke up the next morning all bruised and bloody and Alison calls to make sure he’s okay, letting him know she’ll be on the trial all day.

Unfortunately for Donnie Pouchie’s second-hand man comes by the store and tells him he wants all the pills back because Jason doesn’t vouch for them anymore, and the guy takes Helena’s nitrogen case as collateral.

Donnie goes home and Helena notices he’s beat up so she offers to help. While she’s cleaning him up he tells her that the drug guys stole a tank and Helena tells him that it was full of her eggs, so she wants to get them back but Donnie refuses.

Helena, of course, goes with Donnie when he returns the pills to Pouchie. He also asks Pouchie for a refund in addition to the tank, because he’s dumb, but Pouchie explains there is no refund. Helena shows up at the door after waiting in the car for a couple minutes and poses as Alison so she could get the tank back herself. She gets the tank but then Pouchie’s niece threatens Gemma and Oscar if they ever enter the business again and so Helena takes it upon herself to deal with them.

She walks out of the room all bloodied up, and tells Donnie she got them their refund. Donnie takes her back home where she cleans herself up and he explains to Alison they came into a bunch of new money.

Definitely not Shay

At Shay’s place, Cosima checks out the file Delphine gave her and sees that she is ex-military, so as soon as Shay gets out of the shower Cosima bounces. She meets with Scott and he helps her realize that she should’ve known all along that Shay was a spy.

Cosima goes to Delphine and tells her that Sarah is in London trying to find the Castor original, and Delphine offers her help to find out who the Castor mole really is.

Delphine then ends up at Shay’s place with two bodyguards, demanding that they’re going to have a conversation. Shay says that she’s not a corporate spy, and when Delphine brings up Castor Shay seems to legitimately not know what she’s talking about. Delphine starts threatening her with a story about a friend she knew who committed suicide.

During this interrogation Gracie calls Cosima and tells her she’s sorry, and it turns out it was Gracie who was the Castor mole because they told her they’d reunite her with Mark. Thankfully Cosima is able to call Delphine before she does anything drastic, but Delphine is not happy when she finds out it wasn’t Shay.

Next week on ‘Orphan Black’