Guardians Of The Galaxy Vol. 2..L to R: Rocket (voiced by Bradley Cooper).and Groot (voiced by Vin Diesel)..Ph: Film Frame..©Marvel Studios 2017

The following article contains spoilers for Avengers: Infinity War.

If you thought the ending of Avengers: Infinity War couldn’t be any more emotional than when you first saw it in the theater, you were wrong. Guardians of the Galaxy writer-director James Gunn has revealed one more truth about the film’s finale that will shatter your already-broken heart into a million pieces.

As you know, or at least I hope you know since you clicked on a spoiler article, Thanos successfully acquires all of the Infinity Stones at the end of the film, snaps his fingers, and then half of all life in the universe fades from existence. The body count includes many heroes, including Groot, who becomes dust in the wind before Rocket’s very eyes.

Before Groot goes, he delivers one last “I am Groot.” It’s sad enough without any translation, but James Gunn has put the whole thing into devastating perspective by telling us what Groot really says to Rocket.

“Dad.” The last thing Groot does is call Rocket “Dad.” All of the Guardians have had to step up and be parents to this Groot (the original one actually died in the first film) since he was a baby, but Rocket was the one who found him, potted him, and looked after him most of all.

This makes Groot’s final moment so sweet and yet so very sad at the same time. It might even be sadder than Peter Parker’s final goodbye to Tony Stark on Titan. Okay, it’s a tie at best, as nothing is sadder than that.