What explanations can actually account for what happened to Denise McGregor?

Any explanation must fit the evidence — and the limits of what can still be known.

Denise was last seen near her home in Pascoe Vale on 20 March 1978. Within minutes, she had disappeared.

In this episode, possible explanations are tested against the constraints established so far: time, distance, opportunity, risk, and the realities of surviving evidence.

Some explanations hold.

Others begin to fail.

This is not an episode about identifying suspects or assigning guilt.

It is an exercise in feasibility — examining what can be ruled out, what remains possible, and why certainty has remained elusive.

Because any account of what happened must satisfy the same conditions.

And not all of them do.

Content warning: This series discusses the sexual assault and murder of a child. Clinical, non-graphic language throughout. Listener discretion advised.

If you have information, contact Victoria Police Crime Stoppers: 1800 333 000 or www.police.vic.gov.au/crime-stoppers