Still on a mission to erase all trace of Laurel from Ashley's (John Middleton) life, Sally argues with her in the church and when Sally storms out, she moves the heater next to the vestry curtain and a huge fire begins.
Sally then leaves and locks the door on her way out, leaving Laurel still inside.
Speaking of her role, Reeves recently told DS: "Sally's mad… I had a bit of a moment where people thought she was quite nice but was threatening Ashley and Laurel's stability, but they might not know that she's actually bonkers."
She added: "This week will give viewers a really good idea about what lengths she'll go to in a bid to replace Laurel. Sally just wants her life. Sally doesn't understand consequences because she lives in her own little world."
Will Laurel make it out of the fire alive?
Emmerdale airs tonight at 7pm and 8pm on ITV1.
> Click here to read our recent interview with Siân Reeves
> Click here to read more about the episodes
