Fans of Breaking Bad are in for a treat as some of the characters from the hit show will be crossing over into with Better Call Saul season 4.

Executive producers Vince Gilligan and Melissa Bernstein, also co-producer of Breaking Bad, teased some of the details about what is to come in Better Call Saul next season during the AMC Summit in New York this week.

According to the Hollywood Reporter, the EPs said the show would be taking a darker turn but promised there would still be humorous moments.

'Season four is so good,' Gilligan told reporters at the 'Masterclass with Better Call Saul' panel, according to THR. 'It gets darker, it gets richer. It's still got funny in it, but on the Venn diagram of Breaking Bad and Better Call Saul, the overlap in the center is getting bigger and bigger.'

He then dropped a spoiler when he said that there would be a character in Better Call Saul who hails from the time of the Breaking Bad prequel.

'There is a very important character — I'm not promising you ever saw this character, but there was a very important character nonetheless from the Breaking Bad era who we're going to meet this year. You're going to be impressed with him,' he said.

According to THR, Bernstein confirmed during the panel that the character in question was Lalo. It's a case of blink and you might of missed it as the character only got a brief mention during one scene back in season two of Breaking Bad.

And then she added to the intrigue further when she confirmed that there would be a couple more characters coming over to the show from Breaking Bad but wouldn't name them.

Season 4 will see the show continue post-Chuck, as the troubled brother of Jimmy died when his house went up in flames at the end of season 3.

The synopsis teases Jimmy going deeper into the criminal world and how this might put strain on his relationship with Kim. 

It says: 'In Better Call Saul's fourth season, Chuck's death catalyses Jimmy McGill's transformation into Saul Goodman.

'In the wake of his loss, Jimmy takes steps into the criminal world that will put his future as a lawyer – and his relationship with Kim (played by Rhea Seehorn) – in jeopardy.

'Chuck's death deeply affects former colleagues Howard (Patrick Fabian) and Kim as well, putting the two of them once again on opposite sides of a battle sparked by the Brothers McGill.'

'Better Call Saul' season 4 episode 1 premieres on August 6 at 9 p.m. ET on AMC.