TUESDAY, FEBRUARY 18

THE VAMPIRE DIAIRES

"500 Years of Solitude" - (8:00-9:00 p.m. ET) (TV-14, LV) (HDTV)

THE 100th EPSIODE: FLASHBACKS TO KATHERINE'S EARLY LIFE - 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. 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. Chris Grismer directed the episode written by Julie Plec & Caroline Dries (#511).