A lot of shady experimentation goes down in Jessica Jones Season 2, but the craziest moment comes towards the end of the season between Trish Walker and Dr. Karl Malus. Bent on gaining superpowers of her own, Trish coerces Karl into developing an operation specifically tailored to her, and the doctor attains a very interesting drug in order to do that. The two need to go to an animal shelter, where they buy the drug FVRCP. So what is FVRCP in Jessica Jones, and what can it tell us about that major Trish cliffhanger in the season finale episode? The drug's appearance could be confirmation of a big part of Marvel comics being introduced onto the show. Spoiler alert: This post will discuss plot points from throughout Season 2 of Jessica Jones. Don't read on if you haven't finished the season.
The bulk of Trish Walker's storyline in the new season of Jessica Jones is her insatiable hunger for her own superpowers. It is an alarming character trait that first arose in Season 1 when Trish took one of Will Simpson's red pills and gained his enhanced strength in order to fight him, but it has grown to scary new levels in Season 2. For most of the season, Trish hides the fact that she swiped Simpson's inhaler (containing a gaseous version of those pills from Season 1), and has been using it to moonlight as a powered do-gooder. Trish's addiction to the power-giving inhaler is compounded by her addictive personality — as we have seen in flashback moments earlier, Trish used to have a really bad drug problem.
Towards the end of the season, Trish runs into a major roadblock when her inhaler runs empty. At that point, her addiction has become so pervasive that she sets out to capture the man that invented the inhaler, IGH's Dr. Karl Malus, in order to get a more permanent fix. She asks Karl to operate on her like he did Jessica, in hopes that she will also gain superpowers.
This is where FVRCP comes in. The drug at the center of Karl's operation on Trish is a vaccination for cats. FVRCP is a commonly administered vaccine in cats, which prevents a number of respiratory and genetic viruses in felines.
So, why is a cat vaccine at the center of a superpower-giving operation? It seems like Karl may be attempting to replicate the abilities of a cat in Trish, and that's a very important implication. In the Marvel comic books, Patsy Walker is a former TV star that becomes the superhero Hellcat, with agility similar to that of a cat. Hellcat also has certain psychic abilities, along with being a well-trained martial arts expert. The explicit mention of Karl and Trish using a cat vaccine as the main component of their experiment seems to be a clear sign that they were attempting to bring Hellcat to life.
But did it work? At first, it seems like Karl's operation on Trish had failed, since Jessica interrupts it midway through, noticing Trish bleeding in IGH's lab and whisking her out of the building. Trish spends the next few days unconscious in the hospital, but then we get a pretty surprising sign that Trish may be becoming Hellcat after all.
At the very end of the season, Trish is out of the hospital and goes to talk to Jessica at her apartment. As she leaves, Trish drops her phone, but amazingly, catches it on her foot, displaying superhuman reflexes. The cat-like ability seems like a definite confirmation that Karl's operation really was successful, and Trish may be exploring the world of superheroes as Hellcat in the third season of Jessica Jones.