While chatting about what Ehrenreich wished he could have said to Ford when they previously spent some time together, the iconic actor himself walked through the doors -- and jokingly demanded that the new Han get out of his chair.
The epic moment -- which has been the one and only interview Ford has done for Solo -- was captured in the video above. Ehrenreich was musing about hearing "pretty incredible" stories straight from Ford about his time on not just the Star Wars films but also the Indiana Jones and Blade Runner franchises, as well as Fugitive. "He said, 'If anyone asked, I told you everything you need to know and you’re not allowed to say a word," the 28-year-old actor recalled.
"He might want to say one or two more things," Mathison pointed out as Ford snuck up beside the actor.
"You're sh**ing me," Ehrenreich exclaimed. "Oh my god!"
"Get out of my chair! Get out of my light!" Ford teased before, of course, saying, "Hi."
Ford joked that he just happened to be in the neighborhood checking out reverse mortgage options before sitting down for the interview, where he promptly praised both Ehrenreich and the rest of the Solo cast.
The 75-year-old actor explained to ET that Solo started with "a fantastic idea" and "a great script" before going on to explain that everyone was cast very well, but Ehrenreich especially so.
"I just thought it was spectacular, and I thought he was so smart about what he did and how he did it," Ford said. "I just couldn’t be happier."
"Wow!... That's pretty unbelievable," Ehrenreich responded to the praise.
Ford then headed back out to see about those mortgages, but Solo director Ron Howard, who helped make the surprise happen, stayed for a little while longer, telling ET about how Ford felt upon seeing the new iteration of Han.
"I have to say, I’ve known Harrison a long time. He can be great, he can be supportive. He’s never effusive," the 64-year-old director said. "And he was so behind it and into it and loved what Alden did. So, I let Alden know that, but I would never even say that to the world, because you don’t speak for Harrison Ford."
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Even though Howard continued to say nice things about him, it seems Ehrenreich was still in a bit of recovery mode after seeing Ford for the first time since they had last sat down for lunch together.
"I can’t describe it... That meant a lot. That was incredible," he explained.
"That’s really special. His graciousness from the first time that I met him and then also him coming in and doing something like this, it just means the world 'cause he's a kind of partner with George Lucas in creating this part. He is this thing," Ehrenreich added. "He created it in a way that I think actors are usually just like serving somebody else’s vision."
The Beautiful Creatures star also revealed his favorite aspect of Han that he was able to bring back to the big screen.
"You’re meeting him at a different point in his life, but I think [if] there’s one thing I love, [it's] how he flies the ship, that it always feels like his bread and butter," the actor said of the character. "There’s a certain vibe that he gets into with that, and I think he’s just the coolest guy."
Ehrenreich wasn't the only one who had to recover from the news of Ford's appearance during Saturday's Solo junket. Donald Glover and Phoebe Waller-Bridge seemed pretty jealous that they didn't catch a glimpse of Ford, with Waller-Bridge joking, "We have to go sniff him out!"
"People keep saying that he's like Superman," Glover added.
Their Solo co-star, Woody Harrelson, was especially psyched because he got to watch video from the moment the surprise went down. "That's so cool!" he exclaimed. "Wow, Harrison!... That's pretty cool, the fact that he walked in."
As for Ehrenreich, he was just excited to get to spend time with Ford both before shooting and during this surprise, as he hopes to be able to emulate his elder's impressive career path.
"He seems, at least to me, to be someone who’s managed to navigate a huge level of notoriety and fame and but stayed in his own path -- like kind of called his own shots," the young actor told ET. "And we just kind of talked about that and living in Wyoming part-time and that kind of thing. The best takeaway was just getting his blessing on the movie and his vote of confidence."
"It’s just that meant a lot to me and he was very encouraging and very supportive and kind of like, You know what you’re doing,'" he added.