The boutique owner and fashion designer's return was teased during the closing credits of Sunday night's (16 June) episode, when fans saw Lucy Mecklenburgh calling someone on the phone and saying, "It's all gone wrong again, I really need to talk to you."
Viewers then saw Lucy meeting the recipient of the phone call – Lydia! – at a café.
Lydia confirmed her one-off appearance via Twitter last night, saying: "I'm back bitches… Just back for the one episode to give my girl a cuddle and some advice #rollonwednesday."
Lucy added: "Yayyy my bestie is back!!!! @LydiaRoseBright x."
TOWIE fans will know Lucy's had a difficult time lately dealing with the fallout from her split with Mario Falcone. On last night's episode we also saw her current love interest Dan Osborne revealing that his ex-girlfriend is expecting his baby.
Lydia, meanwhile, was last seen on The Only Way Is Essex back on the Christmas episode, where she told Lucy she needed to get away from ex-boyfriend James 'Arg' Argent.
She said at the time: "End of an era, thank you everyone for supporting me on TOWIE. Had the best experience ;( I'm so grateful. Hopefully I'll be back soon. You never know what the future holds. Essex has got a strong hold on my heart. I love you all."
Will Wednesday night's one-off appearance turn into something more? Fingers crossed. We've quite missed having Lyds on our screens.