|Original Airdate||July 26, 2003|
|Guest Characters||* Blackfire|
|Written By||Amy Wolfram|
|Directed By||Alex Soto|
|Previous Episode||Final Exam|
|Next Episode||Divide and Conquer|
Sisters is the second episode of the Teen Titans series and season one.
The Teen Titans (well, just Robin and Starfire) are enjoying a fair when Starfire is suddenly attacked by an alien probe. The team succeed in fighting it off, but are left wondering where it came from. They return to Titans Tower, where they find that Starfire's sister Blackfire has stopped by Earth for a visit.
Starfire is overjoyed to see her at first, but Blackfire quickly begins taking over Starfire's place on the team. They visit a disco, where Starfire is left alone when the other Titans manage to find partners for a dance. Robin tries to talk to her, but Blackfire drags him off. Starfire once again encounter the probes, which manage to overwhelm her. The Titans come to her rescue, where Blackfire destroys all the probes with starbolts from her eyes. Robin asks her how she did it, where she replies with a hint of smile that it was just a lucky guess. Cyborg remarks that they need that kind of luck and offers Blackfire a spot on the team! Starfire, who is still recovering from the attack, gasps in shock.
Starfire is sad about this at first, but then comes to the decision that the team will be better off without her, and decides to leave. Robin convinces her to stay, but just then, the aliens who sent the probes show up and take Starfire captive. Robin attacks their ship and sets her free, but just as the other Titans show up and prepare to battle, the aliens announce that they are Centauri police, here to capture a Tamaranean thief, who they say is Starfire because she's a Tamaranean, but she'd never even been to the Centauri Moons. But the Titans know who has been to Centauri and that there's another Tamaranean on Earth. Seeing the Centauri Moon diamond on Starfire, Robin realizes they must be talking about Blackfire because she's been to the Centauri Moons; that's where she'd gotten the diamond, and she told Starfire herself. It all turns out that Blackfire had stolen the diamond and gave it to Starfire and was only pretending to be the Titans' friend so she could get away with her robberies in Centauri and let her sister take her place in jail. The Titans find that Blackfire is trying to escape Earth to return to Tamaran. Starfire, enraged, flies after her sister, and engages her in combat long enough for the Centaurians to capture her. Blackfire is taken away by the Centauri Police, vowing revenge on her sister. The scene changes, and Starfire is shown sitting alone in which Robin joins her. He encourages her by saying that no one will be able to replace her, which reveals a smile on her face.
- When Kai told the Titans that they're all under arrest, Starfire's armband disappears. When Cron said that Starfire had committed high crimes throughout Centauri and Starfire said she'd never been to Centauri, her armband reappears. Then when Robin gave Kai and Cron the stolen diamond Blackfire gave Star and said they've been chasing the wrong girl, Star's armband disappears again.
- When Starfire tries to recite her verse, Cyborg's eyes or both real. This is obviously an animation error.
- In Date with Destiny Robin said that he danced once and he disliked it. But in this episode, he is shown dancing with the other Titans except Starfire and he doesn't show any hatred.
Refering to the fact that Starfire and Blackfire are sisters.
- Blackfire: (laughing while dancing) Now, don't tell me you big, tough superheroes are afraid of a litte dancing.
Beast Boy: Betcha Cyborg can do the robot.
- Raven: (after being handed a big chicken doll as a prize) A giant chicken. I must be the luckiest girl in the world.
- Starfire: (About Blackfire) She will be a better Titan than I ever was...
- Starfire: Hello, Robin and... my sister! Am I interrupting?
Robin: Not at all. Blackfire was just showing me some alien martial arts. How come you never taught me these cool moves?
Blackfire: Probably because she doesn't know them. I always was the better fighter.
- Starfire: Hello, sister.
Blackfire: Oh, you're mad. I know I should have told you I was leaving, but you know how I hate saying goodbyes and-
Starfire: You are a criminal and you were going to let me take your place in jail.
Blackfire: Well, yeah.
Starfire: You will give back what you have stolen and turn yourself over to the police.
Blackfire: And what will you do if I don't? (Blasts Starfire with a starbolt), I Always was the better fighter.
- Starfire: Not anymore. (Flys up toward her. Blackfire starts a shower of purple starbolts; Starfire flies through them and shoots her sister's right hand; Starfire then rises over Blackfire. Blackfire prepares to blast her and she is captured by the Centauri Police)
Centauri Police: Blackfire of Tamaran, you are under arrest.
Starfire: Farewell, sister. Although you did attack and betray me, it was still very nice to see you.
Blackfire: Next time, it won't be so nice. I will get out of jail, little sister, and I will get even.
- Beast Boy: See? She thinks I'm funny! Raven: Statistically, I suppose someone has to.
- Starfire: So- Beloved sister- what brings you to Earth? Blackfire: I was in the quadrent. Thought I'd see if earthlings like to party.
- Starfire: We could visit your favorite depressing café. Raven: Already been. It was open mic and Blackfire wanted to share. Your sister's poetry is surprisingly dark.