The first return trip of a new air mail service from Australia to Britain.
Titles read: "AIR MAIL SERVICE FROM AUSTRALIA".
Brief ceremony on a balcony where Australia's Governor General (unnamed) hands a mail bag to Captain Brain of Imperial Airways for the first return journey to Britain on a new airmail service. The Captain goes out to the flying boat on a launch while the Governor General has a little difficulty in cutting the ceremonial ribbon that ties the flying boat to the shore. He eventually cuts the ribbon and the seaplane takes off.