Grey’s Anatomy showrunner on the ‘biggest challenge’ of season 16

Grey's Anatomy showrunner Krista Vernoff has shared the "biggest challenge" of season 16.

The long-running medical drama returned to telly screens in North America earlier this week, with a drama-filled episode that addressed a number of big cliffhangers. But it also proved to be particularly challenging, according to Vernoff. She told Entertainment Tonight:

"I'm always looking to keep the show fresh and alive. That is a complicated challenge, 16 seasons and over 300 episodes in. "The biggest challenge was figuring out how we were going to follow through on the firings. "Having Bailey fire Richard and Alex and Meredith -- one of the originals firing the other three originals was a pretty bold move and we wanted to make sure that we played it through with real consequences and dramatic stakes, and I think we've done that successfully."

And the Grey's showrunner also gave an update about her plans to bring a former cast member back to the show. Earlier in the summer, Vernoff said that she was "trying to get someone back" for the upcoming season - but noted that it was more of a "maybe" at the moment. Many fans have wondered if the character in question could be Kate Walsh's Addison Montgomery, Sarah Drew's April Kepner or Sandra Oh's Cristina Yang. Vernoff told the publication that it was an "ongoing effort" to get the character back, adding:

"If I can make it happen, it'll be exciting and if I can't make it happen, we have other exciting things happening. "