Complex sentence: After Sienna is released, Tom and Peri Lomax (Ruby O'Donnell) start a bullying campaign against her, and Peri helps Tom to set Sienna up by kidnapping her niece Rose and planting her in Sienna's flat.
Split into simpler sentences: After Sienna is released, Tom and Peri Lomax start a bullying campaign against her. And Peri helps Tom to set Sienna up by kidnapping her niece Rose and planting her in Sienna's flat.