Jeremy first meets Waverly when she sneaks inside his laboratory, where Black Badge keeps all the weird creatures captive, and hoodwink a into teaching her how to open all the security doors at once, including the one blocking Wynonna’s progress. But when Waverly tries to knock out Jeremy and his head starts to bleed, the soul-sucking demons there go berserk with bloodlust. In the heat of the moment, Waverly confesses her real intentions to him and he goes ahead and opens up the checkpoints.
Jeremy now lives and works in Purgatory after being sent there with Wynonna's new official Black Badge team. Waverly gives Jeremy the contained, dead spider monester, so that he can examine it at the Earp home, where Jeremy works out the the spider Wynonna shot was actually a baby. And the mother has yet to be apprehended. Later, back at the lab, Jeremy gives the Earp sisters a crash course in demonology: in decimating the egg sacks, they cleared a path to an energy source and seal which other supernatural creatures can now access unimpeded.
When questioned about his relationship with Dolls, he mentioned that Dolls was "the only one who understood what happened to (his) mom", but does not elaborate.
After being temporally being held hostage by Jaxon once he arrives at the bar demanding his loot back, Wynonna is prepared to hand over the case to save Jeremy's life. However Dolls bursts out of the basement and breathes fire on him, thus saving everyone in a bar and the case.
At Purgatory's Black Badge HQ, Jeremy digs underneath Earl Earp's plate to find an ensign that was coated over. This same coat of arms is emblazoned on the Purgatory Volunteer Fire Department depot. Jeremy intends to return to Black Badge to find more information about the plate. However Jeremy finds that Black Badge is now gone.
After having his research on the seals stolen by the Widows, Jeremy follows his hunch to the basement of Doc’s saloon, where he thinks the next seal is located, which is correct. The saloon, once a Masonic lodge, comes equipped with a hatch that contains the second seal.
Jeremy helps Dolls in staking out the Gardner home in the event Tucker waltzes back. Jeremy finds a swatch of veil he picked up in the saloon after their fight with the widows and takes it for analysis.
Back at the sheriff’s office, Doc is gearing up for another blast from his outlaw past — that is, arming himself with enough firepower to blow up St. Petersburg — when Jeremy requests his and Dolls’ help in the lab. All six hands are needed to capture the vaporous toxin emitted from the slip of veil, which Jeremy can then use to mix up an antidote. Jeremy uses a binding spell to draw out the vapor: but instead succeeds in binding them all together with invisible chains. Right after binding all three of them together, the phantom bounty hunter Bass Reeves looking for Doc catches him, and strings him up by the neck. Inadvertently, this dude nabs the rest of the fellas as well — something he didn’t expect. Dolls, Doc, and Jeremy perform a bit of ballet to disentangle themselves from the rope, and knock out Reeves.
While trying to evade the phantasmal Reeves, they end up running into an entire squadron of ghostly bounty hunters. Reeves reads Doc his crimes: apparently he had sex with the wrong judge’s woman. Twice. Looks like two wrongs don’t make a right. The hour of execution approaching, Dolls recognizes Reeves for who he really is: the famed US Marshall, the one who inspired Dolls himself to dedicate himself to the law. Dolls flashes his badge, and it’s much bigger than Reeves, making him a superior officer. Dolls orders the men to stand down, and they do.
Dolls and Jeremy find a fingernail pried from Beth Gardner’s supernatural finger in the basement of Doc’s saloon, leading them to the conclusion that she’s a Widow. Dolls brakes into the Gardner residence ready to smoke the Widows once and for all. But they won’t go without a fight. Jeremy tries to intervene, but ends up getting knocked out by Widow vapor.
Jeremy arrives at the hospital after Nicole has been poisoned with a smidgen of hope: if they can extract some more venom, he might be able to synthesize an antidote. But that would mean more Widow contact. Wynonna has roped Rosita into helping Jeremy, by threatening her with Peacemaker, develop the anti-venom, As her Revenant constitution might be able to withstand the assault of the poison. Jeremy is opposed to the idea of using Rosita unwilling but she injects the venom nonetheless. He is able to great the anti-venom in the end, however it is too late as Waverly already strikes a deal with the The Iron Witch.
In the new reality created by the The Iron Witch's wish for Wynonna to have never exited Jeremy and Waverly are close friends who are planning her wedding. Doc succeeds in jogging Jeremy’s memory of the true reality, and winning his confidence by giving him his hat. After Dolls kills Doc and is mortally wounded himself, Jeremy finds him by the side of the road, dying and having killer’s remorse.
He goes on to meets up with Rosita, fills her in on the death count, as well as a conspiracy theory he has: Black Badge is poisoning the water supply with forget-me-drugs, and they all drank it. They go to the Earp barn to investigate. They meet Nicole and Waverly inside who are looking for trophy in hopes of undoing the wish. Waverly’s plan is to detonate all the drugs Rosita cooked up, which will set off a conflagration that can destroy the trophy by fire. They detonate the barn and are returned to their own reality.
And at Black Badge HQ, Jeremy and Nicole’s Bobo brainstorming session is cut short when the White Widow bursts in looking for Wynonna and her baby. She promptly knocks out the two out with her breath, and wrangles them for bait. After being saved by Wynonna, Doc and Jeremy leave to tracked down Bobo at the mine, but the demon’s powers are stronger than ever. Bobo powers have no effect on Jeremy's gun as it is made of plastic, however he notes the metal in Jeremy's body and threatens to rip it out. Doc manages to overwhelm Bobo and impale him on some spikes. Jeremy tells Doc he must leave now in order to see his child before they are taken out of Purgatory.
- Has a weakness for pistachios.
- Knows the periodic table forward and backward.
- Likes reading Doctor Strange Comic Books.
- Claimed to have had sex "one and a half times".
- Has a signed Baywatch (2017) poster.
- In I Hope You Dance, Bobo threatens Jeremy by remarking that he has a lot of metal in his body. Jeremy explains that it's the result of a car accident from when he was 11. In Waiting Forever For You, we learn that at this time, he had been stuck in the car, with the body of his dead mother, for 3 days.
- Jeremy says that he can sense when his friends are scared.
- Featured in the Purgatory Case Files, an interactive narrative that ran throughout Season 2.
- Varun Saranga has said that his personal favorite episode from Season 3 is No Cure For Crazy.
- In The Other Woman it is mentioned by Maeve Perley that she doesn't want to posess his body because he is not purely human.