A journalist sets out to report on a minor earthquake in the Australian outback, and finds that the tremor was a result of a small nuclear explosion - part of an extortion threat that has the government fearing nuclear blackmail. With the help of local reporters, and despite the harassment of the security agencies, he sets out to avert the crisis.

Barry Newman
as Barney Duncan

Bill Kerr
as Willliam Ashby

Trisha Noble
as Gillian Boles

Alwyn Kurts
as Jack McGinty

John Ewart
as Sam O'Bannon

Bruce Spence
as Towie

Willie Fennell
as Old Alf

Vincent Ball
as Prime Minister

Erin Pearce
as Ernie Kramer

Noel Trevarthen
as Kimball