Gemma is set to leave the soap later this year, and viewers will watch Rachel leave the village in what has been billed as an "explosive storyline".
Details about the storyline are being kept under wraps, but this will be a permanent exit for Gemma, who has only returned to the soap in the last four months.
Emmerdale fans were shocked earlier this year when Gemma made a surprise return as Rachel after giving evidence at Charity Dingle's court case.
"It was fantastic coming back to Emmerdale for the surprise return in January," said Gemma. "Keeping it a secret was hard and I didn't even tell some of my closest family and friends.
"I was thrilled to stay longer than the couple of months I was originally contracted for and I'm now looking forward to my next chapter and future roles."
When Rachel returned to live in the village in January, she fought for for ex-lover Sam Dingle who had began a new relationship with Tracy Shankley.
After getting back with Sam, she then found herself fighting for her son Archie, following Jai Sharma's persistence of wanting custody of their son.
Producers have told soap fans to "stay tuned" for more details on Rachel's exit.
Gemma, who made her debut on the soap in 2011, added: "I don't want to give away details about my exit other than to say there is a lot more to happen before I go - and I'm very excited and proud of what's coming up on Emmerdale."
For exclusive competitions and amazing prizes visit Reveal's Facebook page NOW!