WARNING: Spoilers for all of Breaking Bad and Better Call Saul.

A lot still needs to happen in Better Call Saul season 5 before the show becomes Breaking Bad. The prequel's fourth season inched us closer than ever before to the timeline of Breaking Bad, but the show still needs to do some work in season 5 (which was confirmed back in July) before Saul Goodman can be ready to be kidnapped by Walter White and Jesse Pinkman and taken out into the Albuquerque desert.

The events of Better Call Saul season 4 not only moved closer in time to Breaking Bad, courtesy of the incredible nine-month-spanning opening montage in episode 7, "Something Stupid", but in terms of its characters as well. We witnessed Mike Ehrmantraut become a slightly colder killer who is in much, much deeper with Gus Fring, concluding with the murder of Werner Ziegler. We saw the commencement of Gus' superlab, which will become vital to building his drug empire and play home to Walt and Jesse. We had to watch, via that aforementioned montage and a number of other heart-wrenching scenes, Jimmy and Kim growing apart. And, of course, we witnessed Jimmy succumb to being Saul Goodman, at least as a practicing lawyer.

Related: Better Call Saul Season 4 Finale Ending Explained

That final moment, in particular, was painful to watch, all but cementing the dark turn we know is inevitable for Jimmy McGill, but while he's on a path he can't come back from, Better Call Saul isn't Breaking Bad - yet.

Gus' Superlab Needs To Be Completed

Gus and Mike in the Superlab in Better Call Saul

The beginning of construction on Gus' Superlab, and the introduction of its designer, Gale Boetticher, were momentous steps for Better Call Saul season 4 towards becoming Breaking Bad. Both play huge roles in the latter, with the lab especially crucial to the story of Walt, Jesse, and Gus.

However, for all Gus and Mike's efforts towards accommodating Werner and his crew, things hit a number of snags and fell further and further behind schedule. That's compounded by the end of the season, when Werner goes AWOL and Mike is forced to track him down and kill him, with the rest of the crew sent back to Germany.

It's quite clearly in no fit state to be used as of the end of Better Call Saul season 4, and despite Gale's insistence that meth could still be made there, Gus refuses until it's 100% complete. It's up-and-running by the time of Breaking Bad - Tuco uses the term in season 2, in reference to building one for Walt, indicating Gus' is already a success, and Gale is working there in season 3 - and since the show will likely take us up to season 2 of Breaking Bad, (although creator Vince Gilligan doesn't know how it ends) it needs to be finished soon.

Related: Better Call Saul: The Biggest Reveals About Breaking Bad In Season 4

Saul Needs To Meet Lalo And Nacho

Bette Call Saul season 4 introduced us to yet another member of the Salamanca family: Lalo, nephew of Hector and a member of the Juárez Cartel. While Lalo, who looks set to serve as a major antagonist in season 5, never actually appears in Breaking Bad, his turning up here does serve as an important bridge between the two shows.

When Saul is kidnapped by Walt and Jesse (both of whom could yet appear in Saul) in his first episode of Breaking Bad in season 2 and taken out into the desert, he at first assumes he's been taken by Lalo, begging for his life and stating that "it wasn't me, it was Ignacio."

That not only confirms Saul has a run-in with Lalo - one that lets Saul know just how dangerous he is - but Nacho too. Nacho is another character who never appears in Breaking Bad, suggesting things don't work out too well for him. While he and Jimmy worked together in Better Call Saul season 1, their storylines have since diverged, and he needs to meet Saul. Both are close to Saul's mind when we meet him in Breaking Bad, meaning he should have crucial run-ins with them in season 5.

Page 2 of 2: What Needs To Happen To Jimmy Before Breaking Bad

Bob Odenkirk Better Call Saul Season 4

Saul Needs To Establish Himself As The Criminal Lawyer In Albuquerque

After an age of waiting for Jimmy to get his law license reinstated, and some manipulation involving Chuck's letter, he is back practicing law, albeit with a catch. He's no longer working under the name Jimmy McGill, but is now operating as Saul Goodman.

Related: Better Call Saul May Have Already Referenced Jesse Pinkman

That itself is a leap forward, but there's a big difference between starting to work under that name and that name carrying the reputation it does when we meet him in Breaking Bad. This Saul, bar a few shady street deals, is largely unknown in legal circles, whereas the one introduced in season 2 of Breaking Bad isn't just a criminal lawyer in Albuquerque; he's the criminal lawyer in Albuquerque.

He's the man with all the connections you could possibly need to stay out of jail or help build your drug empire. Whatever scheme you need running or tight spot you need getting out of, if you're a member of the criminal underworld, then you better call Saul. By the end of Better Call Saul season 4 he's only just starting out, so season 5 - which might have another time jump - needs to finally show us Saul Goodman, the lawyer.

Jimmy & Kim's Relationship Needs To Be Resolved

Bob Odenkirk as Jimmy McGill and Rhea Seehorn as Kim in Better Call Saul

"It's all good, man."

Four simple words, and yet they were enough to drive daggers through the hearts of Better Call Saul and Breaking Bad fans everywhere. Yes, they confirm Jimmy has turned into Saul Goodman, at least for the purposes of working as a lawyer, but they also mean much more than that.

Related: Better Call Saul Flashforwards May Be Set Before Walter White's Death

It's Kim's response to this, and to the reveal of just how sociopathic Jimmy has become, that is truly devastating: the shock, the confusion, the sadness. This, more than any of the innumerable schemes run by Slippin' Jimmy, is a huge wedge between the pair.

All throughout Better Call Saul, Kim has been a major question mark. She's never mentioned in Breaking Bad, which means that something has to happen to her: something that would mean Saul literally doesn't talk about her once, even in passing.

The best case scenario is that they break-up. They've been growing apart for some time anyway, and with this turn from Jimmy to Saul, it'd be a natural progression. The worst case scenario, on the other hand, is more in line with what happened to Chuck, and that Kim dies. Either way, the relationship between the pair needs to be resolved in Better Call Saul season 5 for Saul Goodman to truly come into being. We should all be very, very worried about Kim Wexler.

Next: What To Expect In Better Call Saul Season 5