The power of three two is coming to Grey Sloan Memorial.

There's going to be a Charmed reunion on season 16 of Grey's Anatomy - and we can't wait. Yes, that's right: Holly Marie Combs and Alyssa Milano will be back on our telly screens once again - and yes, they'll be playing sisters. People report the reunion will be taking place as part of ABC's Cast From the Past Week,  with the special episode airing on October 10. The publication report the pair will play the siblings of a patient, who has been left brain dead after a accident at a construction site. Throughout the episode, they will have to make the decision whether or not to keep their sister on life support. The episode will also reunite Combs and Milano with Grey's executive producers, Krista Vernoff and Andy Reaser, who were both writers on Charmed.  It comes as Vernoff recently revealed she was "trying" to get a beloved character to return to the series. “I’m trying to get someone back,” she told TVLine earlier this summer at the Television Critics Assoc. summer press tour. "I'm trying to get someone back. There's someone I'm hoping will make an appearance this year, [but] it's a real maybe. I'm trying." OK, so she didn't specify just who the possible returnee would be - but given that she's hoping they will make an "appearance", it doesn't look like the mystery person may be sticking around for very long. Hmmm...we're hoping it won't be too long until we find out for sure.