Speaking to TV Guide, Julie Plec explained that the relationship between Luka, his father and Elijah (Daniel Gillies) will soon become clear.
She said: "We learn a lot more over the next few episodes about why [Luka and his dad are] with Elijah, what it is they want, what's driving them, what side they stand on and where they stand with each other as father and son."
Plec also revealed that the characters will begin to have a big impact on Bonnie (Katerina Graham).
"Their relationship gets really complicated and it really complicates Bonnie's life specifically as she learns more and more about them," she teased.
The Vampire Diaries airs on Thursdays at 8/7c on The CW in the US and on Tuesdays at 9pm on ITV2 in the UK.