Knight reprised his character when we were transported once again into Meredith's COVID dream to the same sandy beach where she reunited with her late husband, Derek Shepherd (Patrick Dempsey). The two friends had several poignant conversations about grief, the afterlife and death -- and had the closure they were never able to have following George's premature death.
Following Thursday's episode, Knight took to Instagram to express his gratitude to original cast members Ellen Pompeo, Chandra Wilson and James Pickens Jr., as well as executive producer Krista Vernoff for bringing him back into the Grey's fold after so many years.
"George O'Malley will always claim my heart," Knight wrote in a brief but emotional message, which was accompanied by a heart emoji.
"Thank you to Ellen, Chandra, Jim, Krista and all the familiar faces for once again sharing your beautiful light," his post concluded.
Knight played George for the first five seasons on Grey's before departing the series in 2009. The character was killed off in the season 6 premiere following a brutal accident in the fifth season finale, which remains one of the most stunning TV developments in Grey's history.
"Old friends are the BEST friends @t.r.knight... but like we aren’t old... we’ve just known each other for a very long time yes yes that’s it....," Pompeo captioned the smiley photo on Instagram back in March.
Knight also reshared the photo on his own Instagram, joking, "I’m just happy we met when we were fetuses."