He wasn’t on the speakers’ list, but Percy Jackson & The Olympians creator Rick Riordan staged a surprise last-minute walk-on Sunday at New York Comic Con with his wife, Becky Riordan.

The couple closed out a jam-packed panel for the upcoming Disney+ adaptation of author Riordan’s beloved, modern-day-mythological fantasy novels about a boy who learns he is the half-human son of the sea god Poseidon.

“Let’s go to Camp Half-Blood and play capture the flag,” a smiling Riordan said from the stage, introducing the last of three exclusive sneak-peak clips from the series, which premieres December 20.

A capacity Comic Con audience — many already in orange and black Camp Half-Blood t-shirts handed out at the door — cheered inside the mammoth exhibition hall at Manhattan’s Javits Center. Then came a five-minute reel showing Percy, played by Walker Scobell, in a crucial early test of his fighting skills at the sleep-away camp for young demigods-in-training.