Cailey Fleming had no idea she was playing Young Sylvie on 'Loki' until she watched the episode

• "TWD" star Cailey Fleming made a surprise cameo on "Loki" as Young Sylvie this summer.
• Fleming told Insider she had no idea who she was playing until watching the episode when it debuted.
• The actress also didn't know the show was getting a second season until watching the finale.
• Visit Insider's homepage for more stories.

When Cailey Fleming was cast on Disney+'s "Loki" as Young Sylvie, a variant of Tom Hiddleston's God of Mischief in the Marvel Cinematic Universe, she was beyond thrilled. 

"Me and my brother are the biggest Marvel fans and I'm obsessed with the Marvel universe," Fleming, who currently stars on "The Walking Dead," told Insider this fall.

He was one of the few people to know about Fleming's secret role on the show.

"We're definitely not supposed to tell anybody," Fleming said of Marvel's penchant for secrecy, adding, "But he's my brother. He's not going to tell anybody."

When her appearance aired mid-June, the siblings couldn't watch Fleming's Marvel debut together. She was in Georgia filming the final 11th season of "TWD" where she's played Judith Grimes since 2018.

During a longer conversation about "TWD," Fleming spoke with Insider about her surprise role on "Loki," how she found out about the show's second season along with the rest of us, and how she hopes to return to the MCU one day as Young Sylvie or someone else.

Fleming had no idea what character she was playing on 'Loki' until she watched the episode for the first time

Despite playing a young girl on Asgard who then gets taken into custody by Ravonna Renslayer (Gugu Mbatha-Raw), Fleming wasn't certain of her Marvel role until watching season one's fourth episode when it debuted on the streamer on June 30.

"Whenever I was filming, I only got my scenes," Fleming said of her time on "Loki." "I didn't get the script for the episode or anything. I had no idea what was going on."

Fleming has some experience with being on secretive sets. The actress previously appeared in 2015's "Star Wars: The Force Awakens," another Disney property, as young Rey.

"Anything Disney, Marvel is very secretive," Fleming said, adding, "'Star Wars' was also top secret. But, when I first booked 'Loki,' I didn't even know who I was playing. I didn't have a character name. I had like an alias name."

Fleming couldn't remember the alias she had for Sylvie, but she said it wasn't until episode four aired that she really understood her character's significance on the series.

"Whenever the show came out and I watched it is when I really knew who I was playing," Fleming said, adding that it didn't matter that she wasn't exactly sure who her character was at the time. "I was so excited just to be in the show."

Fleming stayed up late to watch episodes of 'Loki' as they were debuting on Disney+. It's how she learned of the show's 2nd season.

It's not just you who's staying up until 3 a.m. ET or 12 a.m. PT (in the US) to watch new episodes of Marvel shows on Disney+. The stars aren't getting episodes in advance either.

"I think the episode came out at two in the morning here because we're in central time," Fleming said. "We would stay up and watch them."

Fleming said that's how she first learned about the show's second season. The announcement was made at the very end of the show in a brief end-credits scene.

"Whenever I saw the credits and I saw there was a season two, I was like, 'Oh boy,'" Fleming said, adding, "What's going to happen? The finale was amazing. They did a great job with that. And now we have the multiverse."

Fleming hopes to return on the show's second season. 

Fleming's ready to return to the Marvel Cinematic Universe (MCU) as Young Sylvie or in another role.

"I would love to do something with dance in it or obviously something else in the MCU, maybe a new character or keep playing Young Sylvie [in 'Loki']," Fleming said when asked what future projects she'd like to work on after "TWD" ends in 2022.

Now that the multiverse is in full swing, who's to say Fleming can't return as Young Sylvie in flashbacks or a variant of the character. It seems like there's a lot of potential there. 

There's no word on when season two of "Loki" may be out. For now, Marvel is releasing three shows on Disney+ next year: "She-Hulk," "Ms. Marvel," and "Moon Knight."

You can see Disney+'s lineup of future Marvel shows here.