The countdown to the highly anticipated series finale of "How I Met Your Mother" continues on Monday with an all-new episode, featuring actor Chris Elliot, who will reprise the role of Lily's very funny and crazy father Mickey.

Fans were shocked in the last episode of the popular CBS comedy when it was hinted that the The Mother might actually be dead at the end of the show. This became evident after Ted realized that he has told his wife all of his alluring stories, which lead him to become overwhelmed with embarrassment about eventually turning into an old man spinning stories, reports the IBTimes.

"I love your yarns. I hope you never stop spinning them," The Mother said. "But, I don't want you to be the guy who lives in his stories. Life only moves forward."

In a promo video for the upcoming episode, entitled "Daisy," Marshall shows up at a doorstep and punches the lights out of the person that opens the door.

According to CarterMatt, the official synopsis of "Daisy" states that: "Marshall is going to end up enlisting Ted and Barney to help him figure out where Lily went when she left in the middle of their fight."

CBS also shared a "Cheat Tweet," writing "Will The Mosby Boys uncover Lily's big secret? What do u think it is? #HIMYM 3/10 @8pm ET/PT."

In addition to Chris Elliot, a number of other guest stars will also make an appearance, including Marshall Manesh as Ranjit, Suzie Plakson playing Judy, William Zabka in character as himself, and Robert Belushi as Linus, reports Hollywood Hills.

"Vesuvius" is set to air on Monday, March 3, at 8 p.m. EST on CBS.

Watch a preview below.