With Transformers: Age of Extinction opening this weekend around the world, earlier today I landed an exclusive interview with screenwriter Ehren Kruger.  Having collaborated with director Michael Bay on the past three Transformers movies (Revenge of the FallenDark of the Moon, and the latest one), I was curious about their working relationship and how things have changed over the years. During the interview Kruger talked about collaborating with Bay, expanding the Transformers mythology in Age of Extinction, if they've thought about where Transformers 5 will go and how they're "laying the building blocks for some other stories we have in the back of our heads," how his original pitch for Dark of the Moon involved Unicron, developing a less expensive version of Age of Extinction when they were unsure if Bay would be back, deleted scenes, their relationship with Hasbro, and more.  Hit the jump for what he had to say. transformers-age-of-extinction-poster-dinobots Collider: You've collaborated with Bay on three movies now, has he changed at all or is the process of working with him pretty much the same? EHREN KRUGER: The process is the same. He's mellowed [laughs]. With each passing year he becomes a mellower guy, but the creative process has been totally the same. Every time out he's trying to top himself and challenge himself, do things he hasn’t done before personally as a filmmaker and then things the audience has never seen before. Every time out he's pushing ILM and the other effects companies to come up with new stuff and just push the envelope on what they can do. So that hasn’t changed over the course of the movies. What ILM is able to do has changed over the course of three movies, but his desire to keep pushing the envelope hasn’t. One of the cool things about the movie is that its not an Autobot and Decepticon story, it involves Lockdown and a whole bunch of other forces. Did you come up with this? Was this a collaboration with Bay? I'm just curious how you guys work together and how this one came together. KRUGER: Well, we agreed very early on that there's so much rich mythology to the Transformer universe that we didn't want the movies going forward to fall into kind of predictable pattern of there are good Autobots and there are bad  Decepticons and there's some issue that they're fighting over and they fight. We thought there's so much more potentially to explore than that, so early on we started talking about themes of creation and origin stories, and that led us to thematically kind of into wanting to explore the origins of the Transformers themselves and Optimus and whether sentient alien robots were the thing that were intended or whether that was someone else's plan gone awry. You guys definitely set up a lot in this movie for future installments. It's definitely the beginning of a new chapter. How much have you already thought about where it can go in Transformers 5 and beyond, or is it pretty much you're writing for this movie and you'll think about that when you start writing the next one? transformers-age-of-extinction-mark-wahlberg-2 KRUGER:  We're writing for this movie in terms of the human story and in terms of coming up with the set pieces and visuals, in terms of the Transformer universe we've had a lot of conversations about where we'd like to go going forward. Assuming the fans respond to this movie and assuming it's successful we're certainly laying the building blocks for some other stories we have in the back of our heads. I'm very curious about how the projects have changed along the way. For example on Revenge of the FallenDark of the Moon and Age of Extinction, did you ever set out to make a movie and go, "Wait a minute this isn't working and we're going to dramatically change the story?" Or have there not been many changes along the way? KRUGER: Well, from my perspective there are a lot of changes along the way, because I'll pitch things and some will be approved and some will not [laughs]. My original pitch for Revenge of the Fallen was a totally different story, 100% different story. That was kind of when I was hired on for the job and then as it came together it became something else. Dark of the Moon was pretty much what I set out to pitch, so we had a version Dark of the Moon at one point that involved Unicron in the pitch phase and that went away, but it was always more or less the plot that the movie turned out to be. The last couple when I've been coming up with the story it's been there at the beginning. So I talk about the themes of creation and the idea of Lockdown the bounty hunter and I got excited about those early on. I'm trying to think of any major story changes with this. There was a version of it which was different when we weren't sure if Michael was going to come back and direct it and then the mandate would have been for something that was probably less expensive of a movie and that would have had the same themes, but it would have been a different animal. Then once Michael fully committed saying he wanted to still play in this sandbox, he's always going to try and top himself. So the smaller version pretty much went away. It always dealt with Dinobots, it always dealt with KSI organization. transformers-age-of-extinction-mark-wahlberg-jack-reynor I'm curious about deleted scenes, from the script you turned into Bay to what ended up on screen, were there a lot of deleted scenes? KRUGER: There are a few, there are a few. Not a lot, not a lot.  Anything specifically? KRUGER: Nothing substantial that really changed the story  that you see in the movie. I am also very curious about the relationship with Hasbro. Obvious Transformers is a hugely successful toy line. Is there any sort of interaction where they're saying, 'hey, we'd love to see this in the movie. Or is it pretty much you doing your thing and then Hasbro reacts to what you're making? KRUGER: We very much tell them what we're interested in doing. We certainly ask their advice, they have years and years of experience with these characters, so we might describe a new character that we'd like to build an Autobot around and ask them what character in their library might suit this for their purposes. They’ve never in all the movies we've done, they've never had any kind of veto power over anything, but they're a fantastic resource.Certainly for their purposes they'd love us to come up with new things and new characters and new spaceships and all that, but we want to do that anyway.We want to keep doing something we haven't done in the previous film. transformers-4-age-of-extinction-mark-wahlberg-nicola-peltz When I spoke to Bay at the Hong Kong junket I got the feeling that he's still on the fence about whether or not he's going to do Transformers 5. I hear him say, "What else can I do?" But at the same time I can see that he still loves the universe. What's your feeling? Do you think he's going to come back? And then of course I have ask where are you in terms of Transformers 5? Are you writing? Are you involved? KRUGER: I have a Transformers 5 in my head.  Whether that will be what Transformers 5 is or I will work on it, who knows at this point? For more on Transformers: Age of Extinction: