Meanwhile, Dexter's sister Debra (Jennifer Carpenter) suspects that her new boyfriend Gabriel (Dave Baez) is using her to write a book about her engagement to the first season's "Ice Truck Killer".
Schlattmann was inspired to set the homicide case in a comic book store when he realized that an Aquaman snow globe on his desk "could easily be a murder weapon".
While drinking coffee with Debra, Dexter is called to a comic book store where the shopkeeper has been bludgeoned to death with a snow globe.
Later, at his Narcotics Anonymous meeting, Dexter falls asleep and has a dream in which he, dressed as the Dark Defender, rescues his mother, Laura Moser.
The following day, Lila confides to Dexter that she went into rehab after getting high on methamphetamine and setting her ex-boyfriend's house on fire, unaware that he was inside.
[1] The poster was rendered by comic artist Tone Rodriguez, with whom Schlattmann had previously worked on a screenplay in development at 20th Century Fox.
[2] When Schlattmann visited Rodriguez's studio in Los Angeles to discuss the art, comic book writer Dan Wickline was also there.
[5] The episode opens in a coffee bar at Coral Cove Marina, which was filmed at Leeward Bay's floating diner, the Chowder Barge.
[7] Eric Goldman of IGN called "The Dark Defender" "a very satisfying episode of the show" and thought that "so far [the cast and crew are] doing a very good job" of replicating the tension seen in the first season.
He was impressed by Dexter's discoveries about his birth mother and adoptive father, but called Debra's romance with Gabriel a "less successful" storyline.
[1] Writing for the Los Angeles Times, Tom O'Neil called the episode a "standout" because of the parts of Dexter's past that it explored.
[10] Blogcritics' Ray Ellis praised the "razor-sharp sense of humor" seen in the episode and thought that "In a season of mostly dreary, bland series, Dexter remains the most daring show on television.
Visiting a comic-book shop, Dexter find himself transformed on a handmade superhero poster from Butcher into The Dark Defender, a protector of the city and the executioner of its predators.
... Dexter describes being "half sick with the thrill, the complete wrongness," when the "dark passenger" inside him takes command.