History Recap / OnceUponATimeS6E4StrangeCase

* AbortedArc: Jekyll is killed off right after being hired by Mary Margaret alongside Frankenstein to flesh out the school's science faculty in the previous episode.

* NotSoDifferent: Jekyll and Rumplestiltskin. Both are men who believe the woman they have eyes on should love them regardless of her own feelings on the matter, and both threaten those women (the former physically, the latter verbally and emotionally) when they are rejected.

* NoOntologicalInertia: Thanks to them being the same person, when Jekyll ends up fatally stabbed and leaks BloodFromTheMouth, [[{{Synchronization}} the same happens to Hyde]] before he collapses.

* AllGirlsWantBadBoys: Jekyll's love, Mary, confesses to Hyde that she could never feel for Henry because of his work. She does, however, feel far more for the passionate and darker Hyde.
** When she finds out Hyde and Jekyll are the same person, she screams she would never love someone as "weak" as Henry, which leads to her fatal fall.

* GenreSavvy: When Gold warns Belle that Hyde is after her, Belle immediately asks what he did to Hyde in the past to anger him.

* OutGambitted: For the umpteenth time, Gold manages to get one over on Regina, this time by forcing her to pour the serum on the Dagger or he'll crush Jekyll's heart.

** One of the children in Mary Margaret's class has a straw hat and is credited as TomSawyer.

** When Jekyll asks Rumple why he has come to him and is giving him aid, he responds in a very similar manner to how he explained himself to Dr. Frankenstein, that he had "a vested interest in your work." It's also a CallBack to Season One, when Gold told Mary Margaret (after she hired him as her attorney to defend her from the charge for Kathryn's murder, that he was "invested in your future."

** When Jekyll asks Rumple why he has come to him and is giving him aid, he responds in a very similar manner to how he explained himself to Dr. Frankenstein, that he had "a vested interest in your work."

The origins of the conflict between Jekyll and Hyde are revealed.

* AdaptationalHeroism: Hyde turns out to be a TragicVillain motivated by a genuine love for Mary.
* AdaptationalVillainy: By contrast, Jekyll is driven to rage when he learns Mary loves Hyde but not him which leads to him accidently killing her. He also tried to murder Belle as revenge on Rumple.

* BewareTheNiceOnes: It turns out ''Jekyll'' has been the true darker side of the two all along who killed his beloved Mary by accident and is out to kill Belle for what he feels is revenge on Rumple "causing" all this.

* CoolTeacher: Mary Margaret is thrown her students react badly to her usual teaching method. She's told that she's going by the old methods from when she was cursed and has to be more herself. She does so by showing Newton's third law via an archery lesson.

* ForcedToWatch: Hyde uses the dagger to force Gold to take them to the Jolly Roger. There, he knows Jekyll will kill Belle to get back at Gold, and thanks to the dagger he can neither stop Jekyll nor bring down the protection spell to let Belle escape, so can only watch it happen.

* GenreSavvy: When Gold warns Belle Hyde is after her, Belle immediately asks what he did to Hyde in the past to anger him.

* GoneHorriblyRight: Gold puts a protective spell over the Jolly Roger to keep out Hyde...only for Jekyll to be the one to attack Belle.

* NoOntologicalInertia: Thanks to them being the same person, when Jekyll ends up fatally stabbed and leaks BloodFromTheMouth, [[{{Synchronization}} the same happens to Hyde]] before collapsing.

* OutGambitted: For the umpteenth time, Gold manages to get one over on Regina by forcing her to pour the serum on the Dagger by threatening to crush Jekyll's heart.

* NoOntologicalInertia: Thanks to them being the same person, when Jekyll ends up fatally stabbed and leaks BloodFromTheMouth, the same happens to Hyde before collapsing.

* ImportantHaircut: Gold does this early in the episode after looking in the mirror. Everyone comments on it, especially both Reginas who say it brings out his eyes. {{Subverted}} later when Belle tells Gold he cut his hair short because he hates the sight of himself following her rejection of him. The real life reason for the change is that Robert Carlyle was filming the sequel to ''{{Literature/Trainspotting}}'' and cut his hair to reprise his role as Francis Begbie.

* TheMakeover: Gold does this early in the episode after looking in the mirror. Everyone comments on it, especially both Reginas who say it brings out his eyes. {{Subverted}} later when Belle tells Gold he cut his hair short because he hates the sight of himself following her rejection of him. The real life reason for the change is that Robert Carlyle was filming the sequel to ''{{Literature/Trainspotting}}'' and cut his hair to reprise his role as Francis Begbie.

* {{Synchronicity}}: Thanks to them being the same person, when Jekyll ends up fatally stabbed and leaks BloodFromTheMouth, the same happens to Hyde before collapsing.

* InternalReveal: The only way to kill one's dark half, even once it is separate from you, is to die yourself. This understandably upsets Regina. Also, we find out just why Hyde, quite understandably, hates Gold's guts.

* MotiveMisidentification: Since in the original story Jekyll had intended to destroy the darker impulses in himself (and in this version he wanted to control them, only to later want to destroy Hyde in the Land of Untold Stories), it seems likely Rumple wanted the serum for the same reason--that because he couldn't receive Belle's Kiss of True Love without losing his Dark One powers, he thought he could use the serum to keep his darker impulses buried and under control, thus letting him be with her. But instead, it's the same as Jekyll only in reverse--rather than wanting to destroy passion and desire as beastly and evil, he wants to destroy his feelings for Belle because LoveIsAWeakness.

* OneDrinkWillKillTheBaby: When Hook suggests to Belle they break open a bottle of rum, she snaps how "I'm pregnant."

* TragicKeepsake: Mary's cameo locket, which both Jekyll and Hyde have a strong emotional attachment to. Ironically, it turns out that Hyde actually loved her and Jekyll, in possessive stalker fashion, ended up killing her (accidentally) when he learned of her love for Hyde; the locket got torn off in the struggle and left in his hands as evidence of his crime.

* ItOnlyWorksOnce: Hyde easily avoids the same stunner Belle had used on him. He openly says "you didn't expect me to fall for that again, did you?"

** One of the children in Mary Margaret's class has a straw hat indicating he's Huckleberry Finn.

-->'''Grumpy''': We are the wall between chaos and order!