Jimmy and Kim's plot to ruin Howard Hamlin was pretty dark already, but Better Call Saul season 6, episode 4 reveals a crucial new detail that drags their plan down to a brand new low. The husband and wife duo of Jimmy McGill and Kim Wexler have evolved into quite the pair of con artists in Better Call Saul, and season 6 charts their most ambitious trick yet - bring professional ruin to Howard Hamlin. Embarrassing Howard would force law firms HHM and Davis & Main to settle their Sandpiper case post-haste, resulting in a massive financial payout for Jimmy, who first brought the suit forward.

The Howard con remains a work in progress, but Jimmy and Kim have already made major moves in Better Call Saul season 6. Jimmy slipped into Howard's elite golf club and planted a fake bag of drugs in his locker, delicately balanced to fall out in view of fellow golfer, Cliff Main (of Davis & Main). Jimmy then sweet-talked the Kettlemans into making complaints regarding Howard's "substance abuse" directly to Cliff's office. The next stage commences in Better Call Saul's "Hit & Run," as Jimmy dresses as Howard, steals his Jaguar, and pretends to throw a sex worker onto the street - right in front of where Cliff and Kim are enjoying coffee.

Related: How Kim Points Out Mike’s Biggest Better Call Saul Tragedy

Jimmy and Kim's overall intention is to convince Cliff Main that Howard Hamlin - his partner in the Sandpiper case - is an unreliable drug addict on a downward spiral, and that's already a rather sinister aim. Howard might be an insufferable, arrogant, pompous jerk, but he's essentially a good and loyal person. Better Call Saul season 6 even shows Howard attending therapy, admirably trying to better himself. Jimmy and Kim might hold their respective grievances against Howard, but they'd struggle to find anything that justifies ruining his professional career. Apparently, that's not even the darkest aspect of Jimmy and Kim's attack. While Kim and Cliff Main are sharing a cup of java in "Hit & Run," conversation turns to family, and Cliff's son in particular. It's here the veteran lawyer solemnly says to Kim, "I'm sure you've heard something about my son's drug problem..." Kim nods, guiltily.

Ed Begley Jr as Cliff Main in Better Call Saul

Suddenly, Jimmy and Kim's plot against Howard takes on an even more evil hue. The crux of their plan is convincing Cliff Main that Howard Hamlin has a drug addiction, but this idea was formulated knowing Cliff had up-close experience in the realm of substance abuse. Better Call Saul doesn't reveal whether only Kim knew about Cliff's son, or whether Jimmy also had that knowledge. Also unclear is whether they deliberately devised a drug addict scam because of Cliff's history, or whether that's just an unhappy coincidence. At the very least, Better Call Saul confirms Kim was aware Cliff Main's son had a drug addiction, yet she still went ahead with the plan to convince him Howard has a cocaine habit.

Until now, the only victim of Jimmy and Kim's Howard scam looked to be the perma-tanned lawyer himself, but by dredging up painful memories for Cliff (who's a completely innocent party), their collateral damage begins to stack up. Jimmy and Kim exploiting Cliff's family trauma is like taunting Kim for having an absentee mother, or running up to Jimmy whilst holding a photo of Chuck and singing "Disco Inferno." The scam begins to move beyond simple con artistry and toward pure old cruelty.

Perhaps Better Call Saul's most earth-shattering outcome would be if Jimmy had absolutely no idea about Cliff's son, and when he eventually realizes, he's appalled Kim didn't think to mention it. Season 6 has already hinted at how Kim's ruthless streak far exceeds Jimmy's - first with the Kettlemans, then later with Mike's "sterner stuff" line. Maybe Kim was willing to exploit a weakness in Cliff Main's past, whereas Jimmy would've drawn a moral line.

More: Better Call Saul’s Office Reveal May Prove Jimmy & Kim’s Howard Plan Fails

Better Call Saul continues Monday on AMC.