Earlier this month, production began in Cuba on director Michael Bay's Transformers: The Last Knight, which is reportedly the filmmaker's last entry in the franchise. We know that Transformers: Age of Extinction star Mark Wahlberg is coming back as Cade Yeager, and it was also confirmed that original Transformers star Josh Duhamel is returning as Lennox. Earlier today, just before the holiday weekend, the franchise's social media feeds gave fans a cryptic hint that yet another original Transformers star may be ready for one last go.

The official Transformers Twitter debuted a mysterious video featuring a message in morse code, which translates to "E I'm Coming for you May 31." Because the attached tweet declares 'Something wicked this way comes', some have speculated that it could mean Shia LaBeouf's Sam Witwicky is returning. And that 'Something Wicked' is a play on the characters last name. The morse code message is similar to one of LaBeouf's lines in the original movies, "Bee, I'm coming for you." It's also possible that this message means a different character is returning altogether.

Shortly after it was confirmed that Josh Duhamel is coming back as Lennox, Tyrese Gibson sent out a video to director Michael Bay, asking for his character Epps to be brought back into the fray. Michael Bay offered a cryptic response, stating he's "thinking" about it in an Instagram post. However, there is yet another possible, and more likley, meaning for this message as well.

RELATED: Mark Wahlberg Is the Highest Paid Actor in the World

As is the case with the first three Transformers movies, 2014's Transformers: Age of Extinction ends with narration from Optimus Prime, as he sends out a message to his creators. It's possible that this morse code message represents the actual message Optimus sent into deep space, since it mirrors the narration from the last lines of that sequel. Take a look at the final line of narration from Transformers: Age of Extinction.

"There are mysteries to the universe we were never meant to solve. But who we are and why we are here, are not among them. Those answers we carry inside. I am Optimus Prime, and this message is to my Creators: leave planet Earth alone, 'cause I'm coming for you!"

It's possible that, on May 31, the Transformers' creators may have a message of their own for Optimus Prime, which could offer a big hint about the story that will be told in The Last Knight. Of course, this is all speculation, so be sure to check back on Tuesday, May 31 to see what will be revealed for Transformers: The Last Knight. Until then, take a look at the video below, and see if you can decipher any more clues.