Martin and Trudy are together and very happy. Martin's relationship with Mack, however, is not so good. Mack is jealous that Trudy, who was always devoted to him, has settled for Martin and, as transport manager, Martin gets the blame when the insurance company refuse to renew the policy on the Mackintosh trucks.

Trudy, however, suggests that she and Martin take over running the haulage as an independent company. Things go well, they get married, and Trudy cuts the final cord with Mack after he pushes her too far, leaving him with the realisation that he needs her a lot more than she needs him.

Then Martin's sister-in-law Sue (Alison Swann) turns up, eight months pregnant and with her husband, Martin's wayward brother Stuart, in jail with no hope of release. Martin had a relationship with Sue before Trudy and it's not long before Trudy realises that the baby is not Stuart's but Martin's. Sue swears she will never tell Martin but Trudy knows this is a secret she cannot live with.

She se