The MCU runs a tight ship. There’s no doubt about that. Movie scripts are often written years before filming, and even after production wraps, every little detail is safeguarded until the final hour (think: The Blip). Sometimes, however, certain scenes or storylines are pulled at the last minute for one reason or another, leaving cast members who were privy to the now-secrets holding onto ticking time bombs. Which is exactly how Guardians of the Galaxy Vol. 3 star Karen Gillan was left sitting on a major MCU secret for a whopping five years.
While in conversation with the D23 Inside Disney podcast, Gillan shared that besides landing the role of Nebula — and excluding any Vol. 3 secrets — the biggest MCU secret she’s ever had to keep was the one about Peter Quill (Chris Pratt) and Mantis (Pom Klementieff) in the Guardians of the Galaxy Holiday Special. You know the one — the curve-ball that Mantis is actually Peter’s half-sister.
“I mean we all kind of knew that Mantis was Peter Quill’s sister. But we weren’t allowed to tell anyone. I mean, you know, that was a big secret for her [Klementieff] but we actually had all found out as a cast, and so we all had to keep that secret together.”
Indeed, back in Dec. 2022, Klementieff confirmed that James Gunn had originally intended to include Mantis and Peter’s relationship in Guardians of the Galaxy Vol. 2. but ultimately decided against it at the last minute. As a matter of fact, Gunn shared the secret with Klementieff as far back as her casting process. “So, I’ve been holding onto this secret for years and it was a little difficult,” Klementieff said at the time.
Mantis, we know now, is the product of Ego’s endless pursuit of an heir capable of harnessing Celestial power. Upon discovering that she was not such an heir, Ego decided to spare Mantis’ life because her empathic powers (namely her ability to put him to sleep) proved useful to him. The reason Mantis decided to keep her blood relation to Peter a secret was to spare him the constant reminder that his father killed his mother.
In keeping Mantis’ secret for nearly half a decade, Gillan, like the rest of the Guardians cast, proved themself a much safer harbinger of spoilers than, say, Tom Holland or Mark Ruffalo, both of whom have notoriously built a reputation as the ultimate spillers of beans.
Both Gillan and Klementieff’s tight lips should serve as useful additions to the DCU’s roster should their desires to hop franchises actually come to fruition. Until then, you can catch both actresses in Guardians of the Galaxy Vol. 3, which premieres in theaters tomorrow, May 5.
