'Mortal Instruments' Audition: Find Out Why It Was So 'Awkward'

'I felt really just sort of like we'd known each other for years,' Bower said during Comic-Con live stream.

To hear "The Mortal Instruments" author Cassandra Clare enthuse about actor Jamie Campbell Bower's audition for Shadowhunter Jace Wayland, you'd think his performance were ordained by the angels above. But as the 24-year-old told MTV News during our San Diego Comic-Con live stream, he was much less confident about his prospects when he showed up to read opposite already-cast star Lily Collins.

"For me, going into that room, where you [Lily] had already been cast — it's such a big deal going in for a screen test for a major movie. I went on to the lot, and there I am on the lot going for an audition, and I was going, 'Oh god, this is just going to be a disaster,' " he recalled. "I didn't feel right for it at all."

But that all changed the minute he met Collins, who inspired an immediate ease within the actor.

"And then the moment I got there, I felt sort of comfortable around you. I felt really just sort of like we'd known each other for years," he said.

In a curious twist, Collins had actually been pushing for Bower to play her sexy-snarky love interest in the urban fantasy from the very beginning.

"I thought I had known him for years," Collins concurred of the meeting. "Jamie had been someone I, from the get-go when they asked me about casting Jace, had put forward from day one. And before he even walked in the room, in my mind, I was really set on this guy coming in and blowing it away. And I hadn't really met him before, and he came in and that was it. I think I knew before I think I knew."

That was more than two years ago now, and when the pair recently watched their audition tape it all felt, well, a bit awkward.

"We watched it back recently, and all I was doing was this the whole time," Collins mimed, twirling her hair. "It was very awkward."

"And I was chubby," Bower chimed in. "I was bloated. I enjoyed a club sandwich or two in my past."

"He's since moved past that," Collins explained.

"I'm on tofu now," he joked.

"The Mortal Instruments: City of Bones," co-starring Kevin Zegers, Jonathan Rhys Meyers and Lena Headey, hits theaters August 21.