'Grey's Anatomy'/'Private Practice' Crossover: Derek Has 90 Seconds To Save A Life (VIDEO)

It was time again for Shonda Rhimes' two hit shows to crossover, as well as two siblings who haven't always gotten along: Amelia Shepherd and her brother Derek. As Derek stars on "Grey's Anatomy" (Thu., 9 p.m. EST On ABC), while Amelia is on "Private Practice" (Thu., 10 p.m. EST On ABC), anytime these siblings get together, it's technically a crossover. But this time, the stakes couldn't have been higher.

This time, they need to put aside their differences and come together to save a life that probably means more to fans of "Practice" than "Grey's." After all, it's the mother of Cooper's child, Erica, who's basically lying at death's door with a brain tumor. To make matters worse, the procedure they need to perform has never been done before, and it needs to be done within a 90 second window or it will essentially leave her brain dead. So either do the surgery and risk that, or don't do it, and she'll likely perish. No wonder it took two hours of television to build to that climactic moment.

It was a tense minute-and-a-half once the clock started ticking, but the doctors managed to finish with five seconds to spare. No one seemed more surprised by their success than Erica herself. In recovery, she marveled as she showed she could life and wave her hand. "I'm alive!" she said with a smile, as Cooper and their son looked on in relief. It all came down to 90 seconds, but it was 90 seconds that gave her a second chance at life.

"Grey's Anatomy" and "Private Practice" air back-to-back on Thursdays starting at 9 p.m. EST on ABC.

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