We're going to start this off by saying spoiler alert for season four. 

No, really. If you haven't seen it yet, and don't want to be spoiled, we recommend turning away now.  Veronica Mars returned for its highly-anticipated fourth season last week - with a brand new mystery that had a game-changing twist. Yes, that's right: the season finale had a divisive twist that changed everything in Neptune for, well, just about everyone. Now, the series' creator Rob Thomas has revealed the reason behind the decision - and how it will impact any possible future seasons of Veronica Mars.  Last chance to avoid spoilers.  They're right below this picture.  For years and years, Veronica Mars fans have been following the ups and downs of Veronica's relationship with Logan Echolls. And the pair finally seemed to get their happily ever after at the end of season four, as they said 'I do'. But that all changed when Logan became the final victim of serial killer Penn Epner, the pizza delivery guy who was behind the murders at the centre of this season's mystery. While he was caught by Veronica and Keith, it turns out he had left behind one final bomb - this time, in Veronica's car. After getting married, Logan and Veronica returned to the house to get their stuff to head on honeymoon. But as Logan left to move her car for street cleaning day, Veronica realised Penn had left the bomb inside her car - she wasn't able to warn him in time, and Logan died in the explosion. The series' creator Rob Thomas told TVLine that the decision to kill Logan was made "before we pitched the revival." He continued:

"Jason Dohring knew going into the season. Calling to tell him that that [we were killing off Logan] was like breaking up with a girlfriend. "It was hard for me to get the words out of my mouth. Jason was great. It stung, of course. "He got why I wanted to do it. He wasn’t happy it was the direction we were going. But he was lovely about it."

He also spoke about his reasoning behind killing Logan off, and how "going full mystery show gives us our best chance to survive." He added:

"Kristen [Bell] and I really want to keep doing more of these [limited, self-contained seasons], like the Sherlock and even Fargo templates. Something where, when we both have windows of availability, we can come back and do it. "The thinking is that we need to survive as a noir detective show. And if we kept doing a show that was half teenage soap and half mystery show, the fear is it would start feeling like nostalgia. "I think there’s a reason you don’t see many hard-boiled detective shows where the lead detective has a boyfriend or a girlfriend; it kind of limits your options. It was like we were cutting off a limb to save a life… I love Jason Dohring. "And I love the character of Logan. But I feel as though we are going to have a better shot of doing more and more Veronica Mars if our heroine does not have a boyfriend or a husband back home."

Meanwhile, Dohring shared his own feelings on the twist with TVLine.  Explaining how he had been left "thoroughly devastated for about the first three days", he said:

"When you’re a part of something you care about so much and you put so many years of your life into… I don’t know, man. "I felt like I gave everything to the role, so a loss like that is gonna be rough. I didn’t even know if I should tell my family. "And there are certain family members I haven’t even told. And they’re going to be stunned, as I was."