A crisis brings Addison back to Seattle Grace Hospital in a crossover episode of 'Grey's Anatomy' and 'Private Practice'.
It is the crossover episode of "Grey's Anatomy" and "Private Practice" on February 5. From the preview given by ABC for the next episode of "Grey's", it is known that Derek receives a call from Addison in some kind of an emergency situation involving her brother, Archer.
Based on the synopsis given on "Private" February 5 episode, Archer will have a severe seizure that Addison and Naomi try to find a cure using every resource possible. And when they don't, Addison seeks the help of the neurosurgeon she knows well, Derek. Also in the episode, now that Derek has the engagement ring, he searches for the perfect way to propose to Meredith.
Archer, played by Grant Show, moves to L.A. to work at Pacific Wellcare but he causes problems between Addison and Naomi.
"Private Practice" is the spin-off of "Grey's Anatomy", which first aired in 2007 and focused on the solo journey of Kate Walsh's character. Addison once made a return for a specialized surgery to "Grey's" several months after "Private" premiered. The crossover may be a multi-episode event in February.