SPOILER ALERT: This article contains spoilers for Season 1, Episode 3 of “Lanterns,” now streaming on HBO Max.

From the series’ opening scene, “Lanterns” sets up John Stewart’s (Aaron Pierre) calling to one day step into his own as Green Lantern. But it’s not until Sunday’s episode that we learn just how long John has been preparing and training — at the direction of his parents — to one day take Hal Jordan’s (Kyle Chandler) title.

“It was a gift to have the opportunity to explore each of these characters with such enormous depth,” Pierre tells Variety of filming Episode 3. “It’s not a given that you get to have this much experience with a character, and live this much with a character in your portrayal.”

In the latest “Lanterns” episode, John is grilled about his difficult life choices by one of the Guardians (Laura Linney) to see whether he’s worthy of replacing Hal. It’s the moment John has been waiting for all his life — the moment he gets to prove exactly why he is worthy of the ring.

“I know exactly why me,” John says at the beginning of the interview.