Rachel Bilson and Autumn Reeser, who once starred together on The O.C., were reunited on Hart of Dixie‘s fourth season finale on Friday, Mar. 27.

Autumn Reeser guest-starred as Olivia Green, the new lawyer in town that takes over for George Tucker, played by Scott Porter. Reeser’s character has a connection with Dr. Zoe Hart (Bilson) because they both come from the big city and struggle to adjust to the quieter life of small-town Alabama.

In September, Reeser posted a sweet WhoSay photo of the costars reuniting.

“Love this girl, such a pleasure to work w/ her again!!” she captioned. “A mini #OC reunion on the finale ep of @CWHartofDixie.”

Rachel Bilson played Summer Roberts and Autumn Reeser played Taylor Townsend on the Josh Schwartz-created drama The O.C., which ran for four seasons from 2003-2007 and also starred Adam Brody, Peter Gallagher, Kelly Rowan, Mischa Barton, Melinda Clarke, Tate Donovan, and Chris Carmack.

It's an #TheOC reunion for #RachelBilson & @autumnreeser on last night's @cwhartofdixie http://t.co/FTClfDNE6q pic.twitter.com/axVpMCmuSJ

— ET Canada (@ETCanada) March 28, 2015

Unfortunately, it was a bittersweet reunion and it turns out it was not only the season finale, it was also the series finale as the decision to cancel the series came on March 15.

Series co-star Scott Porter alerted fans to the sad news of the cancellation last week

“Folks wondering why #HartOfDixie got canned? Simple numbers game folks. Ratings still matter and dictate wins and losses. You have to WATCH,” he wrote.