About to be a father in two different eras, Gary is feeling under pressure and starts smoking 1940s cigarettes in Yvonne's presence. Meanwhile, in 1942 Gary is accused of being a fence after her places an advert in the Times saying he would like to buy Swiss watches.

Yvonne and Gary agree to babysit their nephew, Arthur, who goes missing during his visit and is suspected of having time travelled to 1942. Meanwhile, both Yvonne and Phoebe are struggling with pregnancy related sickness, and Gary struggles to find his place in either era.

Whilst Yvonne is in Korea on business, Gary and Ron concoct an elaborate scheme so that Gary can spend the week on holiday with Phoebe in 1942. When Gary's father unexpectedly turns up, Gary discovers his father has been keeping his own time travelling secret.