'Once upon a time' season 5B spoilers, plot news: New and returning characters, epic moments of Emma and Henry

The second half of of ABC's "Once Upon a Time" season 5 will soon invade television as it premieres on March 6, marking the 100th episode of the series.

In an interview with Variety, creators Adam Horowitz and Edward Kitsis confirmed that the 100th episode will be a two-hour story: the first half will shed light to the mysteries presented in the first half of the year, and the second half will focus more on characters Merida, Mulan, and Ruby.

Here are other things that fans of the series know n so far:

First, "Labor of Love," the 13th episode, will introduce new characters like Hercules (Jonathan Whitesell) and Meg (Kacey Rohl), revealed The Hollywood Reporter.

There will also be a lot of exciting characters to look forward to, such as young Snow White (Bailee Madison) and Hades (Greg Germann). Old characters who will be making an appearance include Prince Henry, Cora, Sidney Glass, The Blind Witch, Peter Pan, Cruella de Vil, Milah, Mulan, Ruby, Arthur, Merida, Guinevere, Zelena, and Hook's brother Liam.

TV Line also reported that one character, who appeared in the pilot series but viewers haven't seen in a while, will return. 

Next, Variety reported that "True Blood" actor Wes Brown will play Gaston -- a hunter and suitor of Belle -- in the "Beauty and the Beast" storyline.

Finally, the bizarre character of Emma (Jennifer Morrison) will now be "The Dark One," and there will be adorable moments between Henry and Emma, after locating the key to Room 8.

Catch the season 5 premiere of ABC's "Once Upon a Time" on Sunday, March 6.