Grey's Anatomy season 17 episode 4 is bringing more people from Meredith Grey's (Ellen Pompeo) beach-world. The previous episodes already featured the appearance of her late husband, Derek Shepherd (Patrick Dempsey). Now, who else is appearing in "You'll Never Walk Alone"?

Another character is coming back in Grey's Anatomy season 17 episode 4, though it remains a mystery as to who could it be. There are a lot of people on the list since the series featured notable characters -- who have come and go -- in the past.

In episode 3, it was confirmed that Meredith has COVID-19 and her condition is getting worse. The preview of the next episode showed that she isn't improving and they still couldn't wake her. That means Pompeo's character remains in the beach dream sequence.

Then clip sees Meredith coming across a house in front of the beach, with the voiceover promises "another person from her past returns." She seems to be happy when she saw the person she's calling, which indicates that this someone is significant t her.

If this person is dead, like Derek, then that rules out Cristina Yang (Sandra Oh), Alex Karev (Justin Chambers), and Izzie Stevens (Katherine Heigl). Yet, it leaves the door open from Meredith's family: her father Thatcher (Jeff Perry), mother Ellis (Kate Burton), as well as sister Lexie (Chyler Leigh).

The latter seemed to be at the top of the list. She is a huge part of Meredith's life, and her exit was sudden. In season 8, she died from the injuries she sustained in the plane crash. Before her death, Mark Sloan (Eric Dane) professed his love to her. Shortly after, he died from injuries in the same plane crash.

However, there is one of the challenges in bringing Lexie back in Grey's Anatomy season 17 episode 4 is the scheduling. CarterMatt noted that Leigh is filming Supergirl in Vancouver at the moment, so it would be difficult for the actress to film two series that require traveling considering pandemic.

If not Meredith's family member, it's possible the series brings other important people into her life, such as George O'Malley (T.R. Knight), Dylan Young (Kyle Chandler), or Denny Duquette (Jeffrey Dean Morgan). Meredith has seen both Dylan and Denny when she's also near death before.

Meanwhile, Grey's Anatomy season 17 episode 4 also sees Owen Hunt (Kevin McKidd) facing a medical diagnosis, Thomas Koracick (Greg Germann) starting to go stir crazy, Maggie Pierce (Kelly McCreary) getting a glimpse in Winston Ndugu's (Antony Hill) background.

There is no new episode coming next week due to Thanksgiving Day, instead, Grey's Anatomy season 17 episode 4 is coming on Thursday, Dec. 3, on ABC.