Warning: Contains spoilers for Doom Patrol season 3 episode 10.
After the Doom Patrol season 3 finale, one of the biggest questions is how and when Dorothy Spinner and the Dead Boy Detectives might appear in season 4. Dorothy (Abi Monterey), the daughter of Niles Caulder (Timothy Dalton) left with the Dead Boy Detectives and Danny the Ambulance to explore her own storyline. After that point, none of those characters are seen or mentioned again for the rest of Doom Patrol season 3. Dorothy’s story was largely central to Doom Patrol season 2 as Caulder tried to find a way to prevent Candlemaker from destroying the world.
After season 2 was cut short due to production issues related to COVID-19, the arc was instead wrapped up early in the first episode of Doom Patrol season 3. The Dead Boy Detectives, Edwin Payne (Ty Tennant) and Charles Rowland (Sebastian Croft) are based on characters that first appeared in Neil Gaiman’s Sandman graphic novels and later received their own spinoff series of comics, Dead Boy Detectives, which introduced the character of Crystal Palace (Madalyn Horcher). The three characters appear alongside Dorothy in the Doom Patrol season 3 episode “Dead Patrol,” where they help Larry travel into the afterlife to save the rest of the squad.
It has been confirmed that the characters will return at some point, but not in the way that many viewers were hoping for. It was announced prior to the "Dead Patrol" episode airing that HBO Max had ordered a pilot for a Dead Boy Detectives spinoff series. No release date has been announced yet. Both Doom Patrol showrunner Jeremy Carver and producer Greg Berlanti will be involved in the show, but rumors suggest that the cast from Doom Patrol will not return, and the characters will instead be recast with a completely different story. Ty Tennant, Sebastian Croft, Madalyn Horcher, and many members of the Doom Patrol audience are unhappy about this, championing the #KeepTheDeadBoysCast hashtag on social media.
While recasting the main characters may not be a popular decision among Doom Patrol fans, they don't need to look very far to find precedence for this decision. Doom Patrol itself was spawned from Titans during a season 1 episode, which saw Beast Boy (Ryan Potter) and Rachel Roth (Teagan Croft) meet at Doom Manor. When the Doom Patrol series eventually aired, Niles Caulder was recast—in Titans he was played by Bruno Bichir—and Beast Boy was never mentioned. It was later confirmed through the Arrowverse crossover event "Crisis on Infinite Earths" that Doom Patrol and Titans actually took place in different continuities, and Dead Boy Detectives could employ a similar trick.
This would leave a potential problem for Doom Patrol, however. Titans never mentioned the oddball team again after they are introduced in season 1, but Dorothy’s story is incomplete and now tied to the characters in a way that would make ignoring their existence very strange. Narratively, it seems likely that Dorothy will need to reappear in Doom Patrol season 4, even with her father’s storyline completed, and if she does then Danny the Ambulance and the Dead Boy Detectives should be with her. While time will tell, it is possible that if they do recast the Dead Boy Detectives for the standalone series, Ty Tennant, Sebastian Croft, and Madalyn Horcher could still return as part of their own continuity in Doom Patrol season 4.