Klaus' (Joseph Morgan) letter to his daughter Hope during season 3's finale may have been the Easter egg to a major story arc in the upcoming season 4 of "The Originals."

The letter was being read via voice-over as Hayley (Phoebe Tonkin) was driving out of town with the bodies of Elijah (Daniel Gillies), Rebekah (Claire Holt), Kol (Nathaniel Buzolic), and Freya (Riley Voelkel).

The last part reads, "Please remember that you are the legacy this family has always desired. The promise we fought to protect. You are and always will be our hope."

A five-year time jump will happen between season 3 finale and the present timeline of season 4. The grown-up Hope will be played by child actress Summer Fontana. A glimpse of her was seen in the first-look trailer shown during the San Diego Comic-Con.

The last part shows the seven-year old Hope asking Hayley, "Mom, are we going to get my dad?" to which her mother replied, "Yes sweetie, I promise."

Klaus is kept alive by Papa Tunde's blade and the lives of his poisoned siblings were anchored to his. Viewers are excited to see how the Mikaelsons will rise again, and Hope has been speculated to play a key role in making this happen.

Hope's genetic lineage makes her a vampire, wolf, and witch altogether, and so far in the story, the only one of that kind. During an interview with TVLine, Tonkin said, "I'm excited to see what kind of personality this little girl has. Even though she hasn't been around her dad for the last five years, I think there's a lot of Klaus in her — good or bad — and I'm excited to see that in this little powerful witch."

"The Originals" season 4's premiere has yet to be announced.