Eps9greys Anatomy - Season: 1

The season one finale of Grey's Anatomy , titled "Who's Zoomin' Who?," originally aired on May 22, 2005. The episode is famous for its massive cliffhanger: the arrival of Addison Montgomery, Derek’s secret wife.

Watch a recap and review of the intense season 1 finale where secrets are finally brought to light:

As the shift ended, a heavy Seattle rain began to fall. Meredith and Derek stood near the hospital entrance, ready to head home together. Their conversation was light, filled with the easy intimacy of a couple falling in love. But the doors swung open, and a woman in a perfectly tailored coat walked in. She was striking, confident, and carried an air of authority that stopped them both cold. "Derek," she said, her voice steady. Eps9Greys Anatomy - Season 1

Derek froze, his face draining of color. "Addison. What are you doing here?"

: A "syphilis train" starts with Alex and spreads to Olivia and George. The season one finale of Grey's Anatomy ,

The woman turned her gaze to Meredith, her eyes sharp. "And you must be the woman who's been sleeping with my husband."

: Izzie and Cristina risk their careers to find the truth about a patient's death. Meredith and Derek stood near the hospital entrance,

The episode ended on Meredith’s shocked face, leaving fans to wait months for the fallout of the revelation that "McDreamy" was actually a married man. Key Storylines from the Finale