Continuity mistake: Nick and Tracy find a crying but uninjured baby, the only mortal survivor of the plane crash, in the wreckage. Yet in part 2, Nick tells Urs that Vachon was the only survivor. (00:10:45)
Continuity mistake: When he's rescuing Tracy at the end, Vachon bites Vudu. But when Nick arrives and props up the dying man, there are no marks and no blood on his neck. (00:39:45)
Continuity mistake: When Cal falls against the canister in the lab and accidentally releases the poison gas, the position of the big yellow lever on the gas pipe shifts back and forth by 90 degrees between takes. (00:34:25)
Continuity mistake: Twice in this episode, Janette refers to having been a vampire for 800 years. Previous episodes established that while Nick was 800 years old, Janette was 1000. (00:14:45 - 00:33:00)
Continuity mistake: The actor playing the bad guy apparently didn't stick to the script. What he says on the phone, telling Tracy where to meet him, and what she writes down for Nick to find later, don't match at all. (00:35:00)
Continuity mistake: The blood stain on Tracy's lapel changes its shape several times between takes. (00:08:15)
Continuity mistake: While the doctor is playing the tape for Reese, Nick and Tracy, the Toronto Leafs hockey team coffee cup on Reese's desk is sitting with the leaf logo turned away from the camera and the hockey player art showing. A few shots later, though Reese isn't drinking any coffee and hasn't touched it, the cup turns itself so the leaf logo is now visible. A little later, it's turned back again. (00:22:30)
Continuity mistake: The clock on Natalie's lab wall jumps forward almost half an hour during a 2-minute conversation with Nick. (00:27:25 - 00:29:05)
Answer: Nick was sick and tired of being an immortal bloodsucker. He wanted to be human, fall in love, get married, have children, grow old and die. As for Janette, according to her, she fell in love and the passion she felt "cured" her of her blood lust.