WARNING: The following article contains spoilers for the Titans Season 1 finale, "Dick Grayson," streaming now on DC Universe.

Titans doesn't give viewers the Season 1 finale they might have expected, with the fledgling superhero team and its allies uniting to battle the interdimensional demon Trigon. Instead, it takes the audience on a dark journey through the mind of Dick Grayson, and, in the process, subverts the most controversial aspects of 1988's Batman: The Killing Joke.

In that influential one-shot comic, by Alan Moore and Brian Bolland, The Joker escapes Arkham Asylum and shoots Barbara Gordon, the former Batgirl, leaving her paralyzed, before kidnapping and torturing her father, Commissioner James Gordon. Although critically acclaimed, and a perennial bestseller, The Killing Joke hasn't necessarily aged well, with some modern readers criticizing its treatment of Barbara Gordon. The 2016 animated adaptation attempted to address that issue, but in the process ended up creating new problems with its Batgirl subplot.

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As the promo for the Titans finale hinted, the increasingly dark events of the episode unfold entirely within the mind of Dick Grayson (Brenton Thwaites), guided by the sinister hand of Rachel's demonic father Trigon (Seamus Dever). Although this dreamscape, as the synopsis calls it, starts off pleasant enough, with Dick and Dawn Granger (Minka Kelly) happily married in sunny California, and expecting their second child, the first shadow falls with the arrival of Jason Todd (Curran Walters).

Confined to a wheelchair, much to Dick's surprise, the second Robin reveals that it was he -- and not Barbara Gordon -- who was shot, with the bullet lodging in his T5 vertebra. Only in this scenario, it wasn't the work of The Joker but instead The Riddler. "You know how The Riddler never uses a gun?" Jason asks Dick. "Well, now he does." On Titans, Barbara isn't hospitalized, but instead missing, which may signal something worse.

It's emblematic of a Gotham City in rapid decline, with Commissioner Gordon now dead at the hands of The Joker in another callback to The Killing Joke. In the comic, the Clown Prince of crime keeps the commissioner chained in an old amusement park where the villain's henchmen beat him, and he's forced to view photos of his mutilated daughter. In that story, Batman ultimately rescues his old ally, but on Titans, he fails. The Joker tortures Gordon for more than a week, texting photos to Batman, but, "By the time Bruce figured out where he was, it was too late."

It's what, in this shadowy fantasy, breaks the Bat, sending him on a downward spiral the leads not only to the execution of The Joker, but also his invasion of Arkham Asylum where, as the episode promo and photos suggested, he also kills The Riddler, the Ventriloquist and Scarface, and many other inmates. But the massacre doesn't end there, as the Caped Crusader also executes the facility's staff.

However, Bruce's descent is also Dick's in this dreamscape. It's a mental Choose Your Own Adventure, with Trigon, who appears in the fantasy as a Gotham police detective, gently nudging the former Robin to make darker and darker decisions. He had the opportunity to remain in California with his family, but he opted instead to fly to Gotham. Once there, he could have returned to a very pregnant Dawn, but he opted to remain. And so on. Unable to help his former mentor, Dick sets out to stop him by revealing Bruce Wayne's secret to Gotham City Police Department and then overseeing the (not entirely logical) raid on Wayne Manor.

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Just as Bruce had his breaking point, so too does Dick. Batman was, of course, expecting a raid, and simply waited for the police, and then launched his own bloody attack. Not even Kory Anders (Anna Diop), who in the dreamscape joined the FBI, can stop him. It's when Batman kills Kory that Dick snaps, ordering explosives planted around the mansion to be detonated. He then walks into what remains of the Batcave, where he finds a trapped Bruce, and kills him. "This is what you always wanted," Dick says, "You wanted me to give in to the darkness, to become you. Well, fuck you, Bruce," he continues in a callback to the first episode, "You win."

So, too, does Trigon ends, because, with that imagined act of murder, Dick Grayson falls under the demon's thrall.

Now streaming on DC Universe, Titans stars Brenton Thwaites as Dick Grayson, Anna Diop as Kory Anders, Teagan Croft as Rachel Roth and Ryan Potter as Garfield Logan, and guest starring Rachel Nichols as Angela, Seamus Dever as Trigon, Minka Kelly as Dawn Granger, Alan Ritchson as Hank Hall and Curran Walters as Jason Todd.