"How I Met Your Mother" Season 9 will be premiering tonight on CBS at 8 p.m. ET with a special hour-long episode. Watch the season premiere of HIMYM season 9 episode 1 here. 

The final season of the popular comedy series will finally reveal more details about the mother and how she came to meet Ted Mosby. After years of telling his kids stories of his life, friends and love life, Season 9 will finally allow viewers to get to know the mother.

The mother is played by actress Cristin Milioti, who briefly appeared at the end of the finale episode on season 8 with a yellow umbrella.

The new season will see the mother arrive on the scene and document how she comes to know each of the main characters on the show. It has been leaked that the mother will come to meet each of the characters one by one, and Ted will be the final one to get to know her.

In a promotional video for the new season released last month, Milioti can be seen sitting next to Alyson Hannigan's character Lily on a train.

The promo video starts with the narrator saying, "Eight years ago - this man - sat down with these kids - to explain how he met their mother." The camera then shows Ted and his two children. The narrator continues, "On Monday, Sept. 23 - See the Mother -- Meet the Mother - Get to know the Mother."

The teaser shows the Mother asking Lily, "Do you want a cookie?"

Lily says to Milioti's character, "Sorry I tried to bite you. "

She responds, "Sorry I swatted you on the nose with a rolled-up magazine."

Meanwhile, SpoilerTV has released the titles and the synopsis for the first three episodes of the brand new season.

Episode 1, "The Locket," will air September 23 on CBS.

The synopsis states: "On their way to Long Island for their wedding weekend, Robin and Barney come across a startling family discovery. Meanwhile, Marshall sees something online that changes the course of his entire journey back east, and Lily confronts Ted about letting go of Robin, on the ninth season premiere, of HOW I MET YOUR MOTHER, Monday, Sept. 23 (8:00-8:30 PM, ET/PT) on the CBS Television Network. Sherri Shepherd ("The View") guest stars as Daphne, a woman on the same flight as Marshall; and Wayne Brady ("Let's Make a Deal") returns as Barney's brother, James."

Episode 2, "Coming Back," will also air on September 23 after the first episode The synopsis states: "When James reveals that he is getting divorced, Robin worries about how Barney will take the news. Meanwhile, Marshall races to find a way to get to New York in time for the wedding, and Ted deals with being alone at a romantic hotel, on a special HOW I MET YOUR MOTHER, immediately following the season premiere Monday, Sept. 23 (8:30-9:00 PM, ET/PT) on the CBS Television Network. Wayne Brady ("Let's Make a Deal") returns as Barney's brother, James, Sherri Shepherd ("The View") guest stars as Daphne, a woman on the same flight as Marshall and Roger Bart ("Desperate Housewives") guest stars as the front desk clerk at the hotel."

Episode 3, "Last Time in New York," will air on September 30. The synopsis states: "When Lily discovers Ted's list of things he wants to do in New York before he moves for Chicago, she becomes frustrated that she is the only person who knows about his plans. Meanwhile, Robin and Barney realize they have very little time together before their relatives arrive for their wedding, on the final season of HOW I MET YOUR MOTHER, Monday, Sept. 30 (8:00-8:30 PM, ET/PT) on the CBS Television Network. Sherri Shepherd returns as Daphne, and Wayne Brady returns as Barney's brother, James."