Now only a day away, "The Vampire Diaries" will return from its winter hiatus and air its long awaited 100th episode, which will be filled with shocking twists, bittersweet reunions and game-changing milestones.

In a promo of the episode, which is titled "500 Years of Solitude," Katherine is seen on her deathbed, while Elena deals with her breakup with Damon and Bonnie continues to serve as the gateway to The Other Side.

The teaser video begins with the news that Katherine survived her heart attack, but is hospitalized and may not live to see another day. In the meantime, Jeremy, Damon, Caroline, Elena and Stefan are drinking and reminiscing about the worst things that the 500-year-old doppelganger ever did to them. Most of them recall how she tried to killed them as Caroline reminds them that Katherine actually killed her.

The CW released an official synopsis of the episode which reads:

"As she faces a new crisis, Katherine (Nina Dobrev) remembers the traumatic night in 1490 when she gave birth to the daughter who was immediately taken from her. Stefan (Paul Wesley) lets Elena, Caroline (Candice Accola), and Bonnie (Kat Graham) know that Katherine's health has taken a turn for the worse while Damon (Ian Somerhalder), Matt (Zach Roerig), and Jeremy (Steven R. McQueen) discuss some of Katherine's most notorious moments.

According to the CW, "Nadia (guest star Olga Fonda) comes up with a frightening plan to protect her mother, and Stefan and Elena are forced to help her. Meanwhile, Caroline is mortified when she realizes she forgot to fill Elena in on the latest shocking gossip, then indulges in a little scandalous behavior of her own."

"Finally, Elena and Katherine share an unexpected moment of connection," the promo concludes.

According to TV Guide, Katherine and Stefan will share an intense moment in the 100th episode when Stefan helps her recall the birth of her child, which subsequently led to the death of her parents.

A new promo shows reveals a snippet of Elena and Damon's breakup and Carolina admitting that she "did a bad thing." Another preview clip shows Elena being consoled by friends after getting dumped.

The 100th episode of "The Vampire Diaries," "500 Years of Solitude," airs on the CW on Thursday, Jan. 23 at 8 p.m.

Check out preview clips below.