'Astrid & Lilly Save the World' Recap: Ep. 4 has Astrid and Lilly battling a new kind of foe: Pop culture

So far in Astrid & Lilly Save the World, our eponymous heroes have gone up against shapeshifters, sadomasochists, and monsters with a taste for testosterone. But it's their next adversary that might be the hardest: a pop culture phenomenon that's swept the town.

A new dance craze would appear to have laid hold of their high school body, and it's spreading like Gangnam Style wildfire into the whole town. But is there something more sinister at play than mere groupthink and peer pressure?

Astrid (Jana Morrison) and Lilly (Samantha Aucoin) are going to find out.

**SPOILER WARNING! Spoilers ahead for Astrid & Lilly Save the World Season 1, Episode 4, "One Rib."**

When Astrid and Lilly arrive at school, a few of their schoolmates are synchronously, and mindlessly, dancing on the lawn outside the entrance. The fad doesn't raise any red flags yet, as dance crazes are all too common in this (and our) world, so our heroes brush it aside.

Besides, Astrid has more important things to think about besides monster hunting: Sparrow (Spencer Macpherson) is serious about going on that date she offered, and they set a day and time. Tonight. It's happening.

Despite Astrid's burgeoning love life, the dance craze is spreading at an alarming rate, depriving its victims of their self-control — again, nothing we haven't seen before. They're dancing into traffic, beating their heads against walls, and arousing the concerns of friendly, local police officer Drew, who speculates there might be a new drug on the market inspiring these new tranced-out moves.

Astrid and Lilly are getting more suspicious as well, and decide to drop by Brutus' (Olivier Renaud) place with some questions. As he's out acquainting himself with human culture (i.e. mall life), the two go through his stuff and find his notebook. They then split up: Astrid to her date with Sparrow at the roller rink; and Lilly back to school, to check up on auditions for Romeo & Juliet.

While in the hallways, Lilly is approached by a flailing dancer. The automaton sneezes on another student, who then starts performing the routine, leading Lilly to deduce that whatever has got a hold of them — it's contagious.

It's the same at the roller rink: mindless teens and tweens stepping through the same moves over and over again. Only this time, they're on wheels. Astrid dips on Sparrow, and links up with Lilly to source some disinfecting supplies. Once together, they sift through Brutus's notebook to determine who they're dealing with, then they go about using their superpowers to find it. And into the woods they go.

Once there, they cross paths with a monster with puffy eyes and goiters, sneezing like a fiend. His Anglicized name is Josh, and unlike their other foes, he fell through the portal by accident and has no intent on killing people. Something about this realm gives creatures from the other side terrible allergies, and he's been sneezing on everyone...

Spreading the dancing fever!

But this Josh is relatively harmless (definitely a first!), and submits gladly to Astrid's improvised surgery on his ribcage, from which she removes a single rib to deposit into the vessel. Our heroes let Josh on his merry, nasal-congested way back to his realm, freeing the rest of the town of the dance craze curse.

New episodes of Astrid & Lilly Save the World premiere on Wednesdays on SYFY at 10/9c.