WARNING: The following contains spoilers for the Titans Season 2 finale, "Nightwing," streaming now on DC Universe.
While the first season of Titans focused on Dick Grayson somewhat-inadvertently assembling a new generation of heroes, Season 2 addressed how they might work together, even while ghosts of the past -- to say nothing of the assassin Deathstroke -- threaten to tear them apart.
However, by the time the season wraps with a climactic battle against Deathstroke, the Titans are reunited, but rocked by the death of Donna Troy, and faced with the losses of Rachel (who returned to Themyscira with her body), and Jason Todd. However, their ranks also expanded with the additions of Conner, now free of Cadmus control, and Rose Wilson, seemingly forgiven for operating as a mole for her father.
As they press forward with this new status quo, a third season has already been smartly set up with not only a "new" leader, with Dick embracing his identity as Nightwing, even as he makes peace with his past, but also some loose threads.
THE RETURN OF RACHEL
Rachel tells Dick she's going to use her powers, which have expanded beyond her understanding or control, to somehow bring back Donna. However, we have no no idea whether Rachel will return from Themyscira with more control of her abilities, or corrupted by them.
If she does come back with Donna, this Wonder Girl might not even be the same. Rachel may well become overloaded trying to resurrect Donna, opening doors for her to become a villain, and to take on her friends. She's admitted she can't be trusted, and that she has a lust for blood, so the stage is set for a sinister return to action.
RED HOOD?
After Jason Todd found out Rose was working with Deathstroke, he felt he had been used again -- just as with Batman and the Titans. Jason returned to San Francisco, but he didn't rejoin his teammates for the fights with Deathstroke and Cadmus. He paid his respects to Donn Troy at the airport, from a distance, and then sped off on his motorcycle.
That suggests he's cut ties with Bruce and Dick, and could very well lead him to abandon the Robin identity, and become Red Hood. He assumed that identity in the comics, having been murdered by The Joker years earlier, and then returned from the dead.
OPERATION: BLACKFIRE
The season's final scene depicts Kory's sister, Blackfire, possessing the body of a woman and shape-shifting into the form we saw earlier, when she communicated by hologram. Clearly, she believes if you want something done right, do it yourself, had has arrived on Earth to kill Kory, her rival for the throne of Tamaran.
However, we don't know if she's come alone. Kory has said Blackfire is a powerful enemy but, luckily, she has a reunited Titans family to lean on when the trouble comes to their doorstep. This will clearly be Titans' own Game of Thrones.
LEX LUTHOR'S REVENGE
When the Titans break Conner free of Cadmus' mind control, as expected, he makes a beeline for Mercy Graves' team. Just as she sees him coming and orders her goons to attack, however, we see one of her henchmen receive a call from Lex Luthor. This plot thread isn't picked back up, however, as Mercy and her team are apprehended immediately afterward. But it's virtually guaranteed that Luthor will be angry by their failure, and determined to reclaim his property -- that is Subject 13, or Conner.
Luthor previously ordered Subject 13 to be terminated, but Mercy simply wanted to impress the boss by weaponizing the Luthor/Superman genetic hybrid for sale on the black market. So to see this asset become a full-fledged Titan, Luthor will seemingly have little choice but to retaliate. It's possible there are other Cadmus experiments to be unleashed in a fight against the Titans.
Streaming now on DC Universe, Titans Season 2 stars Brenton Thwaites as Dick Grayson, Anna Diop as Kory Anders, Teagan Croft as Rachel Roth, Ryan Potter as Garfield Logan, Curran Walters as Jason Todd and Conor Leslie as Donna Troy, with Minka Kelly as Dawn Granger, Alan Ritchson as Hank Hall, Joshua Orpin as Superboy, Chelsea Zhang as Rose Wilson, Chella Man as Jericho, Drew Van Acker as Aqualad, Esai Morales as Deathstroke and Iain Glen as Bruce Wayne.