Mary McDonnell, who most recently played President Laura Roslin on Battlestar Galactica, is in talks to join the cast of Grey’s Anatomy for a multi-episode arc.

No details have yet been revealed about the character Mary McDonnell will play on Grey’s Anatomy, but certainly there’s plenty of speculation. Some Grey’s fans are guessing/hoping Mary McDonnell will play McDreamy’s mom, but she could certainly come on as a patient, doctor or other character’s relative.