Ackles dons the Soldier Boy costume and shield once again in an image from the set. He’s seen making, not the peace sign, but the “V” symbol for Gen V. (Get it right!) Details on the cameo are being kept under wraps.

The actor took the stage during a Supernatural fan convention back in early April and told the crowd he filmed a small appearance in Gen V, which he probably wasn’t supposed to do, but here we are. He mentioned that the “little bit” he filmed was heavily improvised. The Boys showrunner Eric Kripke, who created the CW’s Supernatural — which famously starred Ackles — was on set with him for the cameo.

“He and I were just, like, we were spitballing ideas and workshopping literally in between takes and coming up with a whole variety of takes,” Ackles said.

The Boys season 3 ended with a climactic battle against Soldier Boy that left the grizzled supe imprisoned in cryogenic stasis, now under the watchful eye of Grace Mallory (Grace Robbins). Kripke told EW at the time of the finale episode that he’s “100 percent” leaving the door open for that character to reappear somewhere down the line.

“The old TV adage is like, never kill anyone unless you really, really have to. Never close a door, open a window,” Kripke said. “We’ll all have to wait and see, but I can’t imagine the series ending without Soldier Boy making another appearance.”

Ackles isn’t the only actor from The Boys to cross over to Gen V, which follows the students of Godolkin University, America’s premier college for young supes. Returning are Jessie T. Usher as speedster A-Train, Chace Crawford as aquatic hero the Deep, Colby Minifie as Vought’s always-frazzled acting CEO Ashley Barrett, Claudia Doumit as Congresswoman Victoria Neuman, and P.J. Byrne as Dawn of the 7 filmmaker and visiting Godolkin professor Adam Bourke.

The series follows Marie Moreau (Jaz Sinclair), a supe with the ability to manipulate and weaponize blood, who arrives on campus as an incoming freshman. She encounters the likes of the size-shrinking Emma Meyers (Lizze Broadway), the fiery wunderkind Golden Boy (Patrick Schwarzenegger), master of magnetism Andre Anderson (Chance Perdomo), gender-shifting Jordan Li (played by both London Thor and Derek Luh), the mind “pusher” Cate Dunlap (Maddie Phillips), and the troubled strongman Sam (Asa Germann). When the kids uncover a sinister secret within Godolkin, they are forced to question the true meaning of what it is to be a hero.

Also appearing are Sean Patrick Thomas as the supe Polarity, Andre’s father who’s on the Godolkin Board of Trustees; Marco Pigossi as Dr. Edison Cardosa, a gifted physician with ties to Godolkin; Clancy Brown as Professor Brink, the head of the School of Crime Fighting; Jason Ritter in an undisclosed role; and Derek Wilson as the supe Tek Knight, a character from the comics.