Although Constantine has frequently brought up comic book canon in references to John Constantine’s past and even adapted the first two issues of the Hellblazer comic into an episode, the series so far has largely been made up of original stories. Woven lightly into those stories, however, is a season arc based on the ‘American Gothic’ arc of Swamp Thing, which first introduced John Constantine into the DC universe, and it’s in ‘The Saint of Last Resorts Part 1′ that this arc finally starts to gain momentum.

Zed once again gets excluded from the party as John heads to Mexico to help old flame Anne-Marie rescue a stolen baby, but at least this time Zed isn’t cut out of the episode entirely. After realizing that there’s more to flirtatious nude model Eddie than meets the eye, Zed finds herself literally fighting off her past as a couple of zealots from the cult that raised her finally manage to track her down to the mill house. Chances are very, very good that this subplot will end up being connected to the story threads uncovered by John and Chas.

It turns out that the baby-stealing culprit is Anne-Marie’s fellow nun Sister Luisa, though this isn’t too surprising because she’s the only named character in the episode who could have possibly done it – kind of like the theme park owner in an episode of Scooby Doo. Once unmasked, Luisa is revealed to be Lamashtu, a demonic sister of Eve, but her hokey Halloween vampire makeup renders Lamashtu a pretty weak and campy villain.

It’s possible that the budget for Lamashtu’s monster makeup was limited in order to leave room for the creation of the Invunche, a genuinely creepy creature foreshadowed in Zed’s drawings before later being introduced in the flesh as a crawling, twitching menace. In fact, ‘The Saint of Last Resorts Part 1′ can boast a few moments of genuinely creepy imagery, such as a tree growing fruit made out of human flesh and the sight of John stuffing a chicken with blood so he can serve it up as a fake offering to Lamashtu.

The most important element introduced is the Brujería, a race of South American warlocks who – like the Invunche – were supposed to be extinct, but are actually the key players behind the rising Darkness that John has been fighting. The kidnapped babies are descendants of the Brujería, though what purpose they were being kidnapped for isn’t made explicit. It’s implied that they would have been used to create more Invunche, since the one that John and Anne-Marie encounter wails like a baby.

The episode provides a nice payoff to the earlier episode ‘A Feast of Friends,’ in which John sacrificed his old friend Gary Lester by allowing him to be slowly and painfully consumed by a demon. This time around, it’s John who finds himself betrayed by a member of the Newcastle Crew, as Anne-Marie shoots him and leaves him for dead so that she can escape with the babies.

It’s nice to see Constantine finally getting some direction after so many monster-of-the-week episodes, which now more than ever feel like filler episodes. Even if ‘The Saint of Last Resorts Part 1′s main villain was ultimately a bit dull and forgettable, the episode ended on a strong note and sets up the potential for a Part 2 that could be a lot more compelling.

To recap our impressions of the season so far, Constantine started out pretty weak and then improved slightly before hitting a plateau. It’s been held back by the fact that the writers are unable or unwilling to push boundaries, and are still playing within the safe zones of Supernatural‘s tamer episodes. Because of that, the threat of the rising Darkness currently lacks much weight or conviction – much like John threatening to drown a baby but being unwilling to even get its blankets wet.

Constantine continues in ‘The Saint of Last Resorts, Part 2′ next Friday @10pm on NBC. Watch the promo below.