When the Boat Comes In S04E09 - Comrades in Arms

Tania's mother, Lady Leamington, gives a party to raise funds for the victims of Franco in the Spanish civil war. Billy treats Bob Randall, son of Jack's old sergeant-major Fred, wounded fighting for the Spanish Republicans. Jack considers himself in debt to Fred who once saved his life. Jessie and Billy get Fred to persuade Jack to smuggle guns to the Republicans. Using a pleasure cruise as cover, Jack sails for Spain with Tania, Jessie, Billy and communist Nigel Scott-Palliser.