Here’s why Dr. Penny Blake left in such a hurry in Grey’s Anatomy season 12 after just 20 episodes. Played by Samantha Sloyan of The Haunting Of Hill House fame, Penny Blake made her Grey’s Anatomy debut in season 11 episode “How To Save A Life.” The Grey’s Anatomy fandom will remember that episode as the one that killed off Patrick Dempsey’s character Dr Derek Shepherd, aka McDreamy. Derek met his maker when his car got hit by a semi after he attended to the scene of a road accident, which is where Penny comes in.
Derek was rushed to the small teaching hospital where Penny worked to be treated for a blunt force trauma head injury. Though Penny pushed for a CT scan for Derek, her superior ignored her which led to Derek’s death. Despite her best efforts to get Derek the treatment he needed, Penny’s part in the death of one of the show’s best-loved characters didn’t exactly endear her to Grey’s Anatomy fandom.
That wasn’t the last fans saw of Dr Penny Blake either. She returned in Grey’s Anatomy season 12 when Callie Torres (Sara Ramirez) introduced Penny as her new girlfriend at a dinner party hosted by Derek’s widow Meredith Grey (Ellen Pompeo) resulting in the most awkward soiree ever. Things got even more awkward when Penny transferred to Grey Sloan Memorial Hospital and started working under Meredith who basically ran her ragged. Although her Grey Sloan colleagues kind of warmed to Penny, whether they – or the fandom – ever truly forgave her for her part in Derek’s demise is debatable.
Towards the end of Grey’s Anatomy season 12, Penny decided to apply for a grant on a whim that would require her to move to New York City without thinking she’d be accepted. After she was, Callie decided to move with her which kick-started a custody battle between Callie and her ex Arizona Robbins (Jessica Capshaw) over their daughter Sofia – another fact that didn’t endear her to the Grey’s Anatomy fandom.
After Arizona won custody of Sofia, Callie and Penny broke up and she was last seen departing for New York in the penultimate season 12 episode “At Last.” However, in the season finale, Arizona let Callie take Sofia to New York where she and Penny were reunited off-screen. That’s Penny Blake’s abrupt in-show departure explained although some TV pundits suspected the character was written out after Callie actress Sara Ramirez decided to leave Grey’s Anatomy. That, and perhaps the fact she was never really a popular Grey’s Anatomy character to begin with.