Danger and violence have always been a part of Sue Dalston's East End life. She was unloved by her own mother, abused by her father, and then brutalised throughout her marriage, so she smashes her husband's head with a claw hammer in a bid for escape. The only thing keeping her sane is knowing that her children are now safe. No one could have predicted the outcome when Sue is put in a cell with Matilda Enderby, a murderess. Their fates become inextricably linked.