December 7, 1958.

Portland, Oregon.

54-year-old Kenneth Martin is 48-year-old wife Barbara

and their three daughters, 14-year-old Barbie,

12-year-old Virginia, and 10-year-old Susan,

leave their home in their station wagon

to travel to the Columbia River Gorge.

When they failed a return,

they were reported missing the following evening.

Just under five months later,

the bodies of Susan and Virginia

are discovered at separate locations in the Columbia River,

and evidence suggests that the Martin's

station wagon crashed into the water.

However, other evidence,

such as the discovery of a blood-stained gun,

which is traced back to the Martin's

surviving son,

points to the family being victims

of an elaborate murder plot,

but this is never proven,

and no trace of Kenneth, Barbara, and Barbie are found.

...