Episode: Season 3, Episode 17
What happens: Meredith has always had a fraught relationship with her world-renowned mother, Ellis. Afflicted with Alzheimer's, Ellis is lucid for a moment and snippily calls her daughter ordinary. Derek, heartbroken that Meredith could die after nearly drowning, looks over Ellis but eventually loses her to a heart attack. Meredith, in her dream state, later sees Ellis, who tells her she's anything but ordinary. In an emotional circle-of-life kind of moment, the dark and twisty surgeon wakes up when her mother dies.