On her first day at work, Sylvia is befriended by Chris Cross, a fellow operator whose mind is more on play than pay.

Sylvia experiences both her first pay packet and her first Saturday shift - when rules are more relaxed under just one supervisor. A chance call from the local barracks leads to a disastrous blind date.

Ronni is fed up with the old-fashioned music that switchboard supervisor Miss Armitage makes them sing in the GPO choir. She decides to set up an alternative-the Teletones, a group modelled on the Beverley Sisters. Dick gets the girls a booking but the date clashes with the choir concert.

Sylvia discovers that the engineers have wired up the girls' private line to a loud speaker and are listening in to all their intimate calls, including details of Pam's affair with her driving instructor Cyril.

An emergency meeting is called when the supervisors discover that the girls have been listening in to the secret Baslow line used by royalty and top ministers.

A boxed cake is brought to the exchange by Miss Marriott and left in the supervisors' room. The girls try to find out who the cake is for, but disaster follows.

Sylvia has to forget her personal problems when a suicidal caller comes through and she has to keep her talking while an attempt is made to trace the number.

Derby's exchange is requested to put forward a competitor for the GPO Personality of the Year and Chris and Sylvia are both nominated as candidates for the regional competition. Chris seems to have most at stake - she is determined to prove to the exchange that she is more than just a pretty face.

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.