'Vampire Diaries': Kat Graham Teases a 'Surprise' Return and More Trouble for Elena (Video)

The Vampire Diaries season four is proving not to be a letdown.

"It's moving pretty quickly. Everything has been very high-energy, high-paced, fast-moving and life and death. High stakes," Kat Graham told The Hollywood Reporter during a recent chat at West Hollywood's Church. (They are currently filming episode two.)

The actress-singer revealed several teases for season four, saying that "Bonnie is going to meet someone who is going to influence her greatly."

Graham, who is releasing a new single sometime this summer and has her Against the Wall EP out, also spoke of a "surprise appearance" from someone viewers are already familiar with.

"You are going to see somebody from Bonnie's -- and from everyone else's past -- make a surprise appearance in one of the first couple of episodes," she said.

The big cliffhanger from season three, Elena's transition into becoming a vampire, will be dealt with in the opener. If she thought the transition would be the worst of it, the Gilbert has another thing coming.

"Elena's already in a transition into a vampire but you'll also be able to see something even worse start to happen to her in the beginning," Graham shared.

Vampire Diaries, which has booked Tod Williams and Grace Phipps for key roles, premieres October on the CW.