Derek Kolstad was dog sitting with a Chihuahua and Corgi mix in his lap when a nightmarish scenario popped into his head: “What would I do if someone tried to kill this f—ing dog?”

The delivered the inspiration for what would become one of Hollywood’s most successful action franchises as Kolstad put pen to paper and wrote the first installment of John Wick. Introduced with Chad Stahelski at the helm in 2014, the film follows its title character, a former hitman, as he sets out to exact revenge after his home is broken into and his dog is killed. Kolstad originally envisioned Wick as an older hitman until he got a call that would change the face of the franchise.

“It was written for a guy like [Robert De Niro] in his early 70s where the dog was 14 years old. It was a gift from his wife and same thing happens, but it was an old dog,” Kolstad recalled during a panel conversation titled “The Character is the Plot” at Malta’s Mediterrane Film Festival last week in Valletta. During the chat, Kolstad was joined by writer and filmmaker Stephen Poliakoff and moderator James Mottram. “I think the body count on the first screenplay was like 11 people. And then I got a call from Keanu Reeves’ people asking, ‘Hey, do you want to meet Keanu?’ I said, ‘Yes.’ And Keanu and I met for two nights a weekend for about three or four months. I remember he said, ‘I’m going to play him as 35.’ As soon as he said that, I realized we couldn’t have a 15-year-old dog. It became a puppy and from there, you just kind of have to roll with it and come to the end of it with the best idea wins. The best idea won.”