What this song renders
The disposal is documented. After the killing the bodies were stripped of the hidden jewels, doused in sulphuric acid, and buried in a pit in the Koptyaki forest. Two of the children — the Tsarevich Alexei and one of his sisters — were burned and buried separately a short distance away, which left two bodies missing from the main grave.
That missing pair is the engine of the whole survival legend. Because the count never closed, rumours of an escaped daughter could grow; for decades the wrong ground was searched. The main grave was located by amateurs in 1979 and officially exhumed in 1991; the second grave with the two missing children was found in 2007 and DNA-confirmed in 2008, proving that none of the four daughters survived.
The song renders all of this through objects and silhouettes — a stripped jewel, a shoe, the pit-fire glow at distance — never through remains. ‘Sixty years’ and ‘ninety years’ mark the long gap between the burial and the forensic closure; the forest, as the title has it, kept the secret.
The acid, the forest pit, the stripping of the bodies, the separate burning of two children, and the resulting missing pair are documented and forensically confirmed. The absence was real — and it is exactly what allowed the survival fairy tale to grow. See Truth & Legend.