Still, it might be close to what I speculated and posted in June...
"hello, everyone here... Here is the Dashiell Hammett story of what happened to Russell H. and Carol C. For decades RH and CC deeply loved each other while maintaining separate lives. They both had an extended loving family and a rewarding public life of respectability. They treasured spending time together because their lives were so busy and they shared a lot of interests in common--the only way they could escape into their world of companionship and intimacy and was to drive off into the Australian wilderness...setting up a primitive dwelling of bliss in the Wonnangatta Valley. They first met when only in their 30s...now in their early 70s both had developed an array of health problems. Having discussed often what they could do to make sure they died together doing what they loved to do...it was decided that they would perished together in the Wonnangatta Valley where they had spent so many beautiful years together. Their last night in the valley was spent setting up their campsite the way they always did. The following morning they had a good breakfast. After which, they carefully set their tent on fire, and disappeared into the bush abyss of their Wonnangatta Valley dreams..."
trujac, Jun 28, 2020
Correction: Now, we know they met as teenagers...