Is it truly better to have loved and lost than never to have loved at all?

Before putting his mortal life completely behind him, Nicholas insists on visiting his family one last time. Risking traveling too close to sunup, Janet and LaCroix begrudgingly accompany him and are slightly singed by the sun. Since his family thought him killed in the Crusades, Nicholas' sudden appearance makes for an enthusiastic homecoming. He then introduces his mother and younger sister Fleur, to his traveling companions, saying that they have been injured in a skirmish and require prompt rest. His mother leads Janette upstairs while Fleur aids LaCroix who is feeling a bit faint. Her gentle kindness and beauty does not go unnoticed by the vampire.  

Fleur and LaCroix meet in the courtyard and discover a mutual attraction. The two are so enamored that they fail to notice that they're being watched by an overly protective, big brother, along with Janette who persuades him not to interfere. Nicholas waits to confront his master, letting him know that he does not approve of the relationship with his sister. LaCroix tells him that he can't help the way he feels. He had not thought it was possible but he is in love with Fleur. Later, LaCroix and Fleur can't help physically expressing their feelings for each other.

Fleur pleads for LaCroix to take her with him. The vampire is very tempted to make it so that they will be together for all eternity. He is about to bite her neck when Nicholas, whose been lurking in the shadows, intervenes. He points out to her what LaCroix is and what he has also become, but his sister has heard of vampires and is not put off by them at all. Nicholas attempts to talk his sister out of becoming a vampire but she insists on being with LaCroix, the man she loves.

Seeing that his sister won't listen, Nicholas makes his appeal to LaCroix. He conveys to him that if he truly loves her, then he should not seek to destroy that aspect of purity which had so attracted him to her in the first place. It is with a heavy heart that LaCroix gives in and allows the woman he loves to be hypnotized into forgetting about him. In return for this unselfish act, he makes an agreement for retribution. He tells Nicholas, "One day when you have fallen in love, I will take from you what you have taken from me now. We're agreed?" Foolishly, Nicholas agrees to the terms.

Some eight hundred years later, as Valentine's Day draws near, Nick finds his heart beating a little stronger for Natalie. He arrives unexpectantly at her apartment and musters up the courage to show his true feelings for her with a real kiss instead of those friendly little pecks on the cheek he normally has for her. Little does he realize that his growing show of affection for her is being carefully monitored by a lovelorn LaCroix who watches through the window from outside and hasn't forgotten their little agreement from the past.

When Schanke delivers some white roses to Nat from, "A gentleman from the 13th century," she naturally assumes they're from Nick, as well as the written invitation to meet for dinner at a ritzy restaurant called Azure. When she arrives at the designated time, she's surprised to find a stranger waiting for her. LaCroix introduces himself and tells her that he has bought out the entire restaurant for the evening in her honor. Meanwhile, Nick has discovered the roses and card that Natalie had received earlier, and realizes that Nat's life is in danger.

LaCroix begins quizzing Natalie on her relationship with Nick to make sure they are indeed in love with each other. With great subtlety, he hypnotizes her into a receptive state and prepares to take her. Nick arrives just in time to stop him, demanding to know why he is breaking his word about interfering in his personal life with his attempt to kill Natalie. LaCroix reminds him of their deal made centuries ago and demands retribution. Since Nick took away the one he had loved, he wants to do the same in return.

Nick denies that he loves Natalie, insisting that he's only been using her in hopes of finding a cure for his immortality. LaCroix tells him to prove it by bringing Natalie over. When it looks as though Nick is willing to do just that, LaCroix stops him because he doesn't want to trade Fleur's memory for such a meaningless gesture. He wants to await a time when he knows Nick would suffer more acutely from the consequences. He flies off, leaving Nick thankful that he had not called his bluff.

The next night, Nat asks Nick about their evening together because she has no memory of the events. He allows her to believe that she drank too much wine and simply tells her that they had a good time together.

Side note: There's no mention about that kiss they shared a couple of nights ago or the fact that they were making goo-goo eyes at each other afterwards while on the job. One can only assume that since Nat was under LaCroix's more powerful, hypnotic spell, Nick was able to use it to make her forget all. What a pity.