The plot of the series follows Adam (James Nesbitt) and Rachel (Helen Baxendale) trying to have children, the fallout between Karen (Hermione Norris) and David (Robert Bathurst) after his affair, and the departure of Jenny (Fay Ripley).
Kimberley Joseph is introduced as Jo Ellison, the new woman in Pete's (John Thomson) life; their fast-developing romance leads to their marriage in the eighth episode, set in Sydney.
She believed Jenny had nowhere left to go in terms of character development, having already given birth to a child and separated from Pete.
Spencer Campbell went to Los Angeles and auditioned former Home and Away actress Kimberley Joseph, who was looking for work in America.
Bullen had originally planned for Jo to be a "big fat truck-driving lesbian type", but the character was toned down when he met Joseph.
[5][6] Despite it being established in the third series that Rachel was unable to conceive a child because of her abortion, Helen Baxendale's pregnancy meant a "twist" was needed in the plot,[7] and the apparently miraculous conception was worked into the storyline.
[9] The breakup of the Giffords' and Marsdens' marriages allowed Bullen to combine different characters in scenes who aren't often seen together, in particular the third episode, which saw Pete and Karen clubbing together.
[9] By this series Bullen was writing the characters as more like the actors who played them, compared to basing them on his friends as he did when Cold Feet began.
[12] Between the third and fourth series, Bullen and Harries did a speaking tour in the Far East and Australia, where they decided to work a trip to Sydney into the storyline for no reason other than it was "a nice place to go".
[14] Shortly before the first episode was broadcast, it was rescheduled to both Sunday and Monday nights to compete with a BBC costume drama and Dalziel and Pascoe.