It's 1961. Ronni is just back from Italy, and Sylvia and Chris have moved into a flat together. Automation of the telephone switchboards threatens to lead to job losses.
Chris is still at war with new engineer Dave Curtis, and Sylvia is dithering over an invitation from Mike. But Ronni is hiding a secret that could have repercussions for them all.
Miss Marriott persuades Chris, Sylvia and Ronni to perform at a GPO charity gala night. But the arrival of a young Australian telephonist threatens to upset all their plans.
Ronni and Sylvia decide to throw a surprise birthday party for Chris. But their plans are almost ruined when Chris realises, much to her consternation, that her enigmatic suitor is not Dave.
Ricky Rocket - a Billy Fury lookalike and guitarist with his own band - tries to recruit Chris to be his lead singer. But a flu epidemic at the exchange could lead to a change in plan.
Chris and Dave are set to go on their first official date. while Miss Armitage finds romance at the Locarno tea dance.
Mike plans a romantic trip to Paris for Sylvia, which leads her to discover a terrible family secret.
Susi and Johnny are ready to tie the knot. Meanwhile, Chris suspects Dave of keeping a secret.