Grey's Anatomy is definitely killing some characters off in season 22 - but the big question is who? During the May finale of the hit ABC series, Piper Perabo played a mother of a patient who brought a highly flammable acetylene tank into the operating room to force Amelia (Caterina Scorsone) to perform a high-risk surgery to save her daughter. The hostage situation also put interns Simone (Alexis Floyd) and Adams (Niko Terho) at risk, who Meredith (Ellen Pompeo) tried to save before it was too late.