In 1931, Walter Ogilvie has money difficulties due to his gambling addiction and reduced hours at work. His wife decides to take in a lodger to help ease their worries. In 2011, Ellie Milliner moves into her sick father's home with her husband and stepdaughter.
Nick agrees to accompany Ellie to a doctor's appointment to discuss IVF treatment, but when a career opportunity arises, he ends up breaking his promise. Meanwhile, David worries the past has come back to haunt him when he receives an unexpected phone call from Joy, and in 1931, Walter's gambling problem causes him to lose his job at the warehouse.
Ellie's struggle to conceive a child is putting a strain on her marriage with Nick, so she decides to ask her father for money to fund IVF treatment, while David visits Frank at home, and becomes suspicious when he finds Joy working there. Back in the 1930s, Elizabeth takes Violet to a backstreet abortionist - but Gracie stops them - Walter angers Billy, and Nora suffers an accident.
Ellie pushes Frank for an answer to her request for IVF money, David reveals the truth about Joy's visa and Nick goes behind Poppy's back and tells Michael to stay away from her. In 1931, a furious Billy tries to hunt down Walter, Sid reveals his real name and Elizabeth and Gracie reconcile.
Poppy's safe return sparks a full-scale row, Frank makes two big announcements after helping Joy by offering her a way back home to Nigeria and Nick prepares to carry out some DIY on the attic wall. Back in 1931, Walter unsuccessfully attempts to hide Billy's body, and is reunited with Gracie and Elizabeth as they make a fresh start to family life.