Fairly entertaining, modest made-for-TV shocker about academic (Forster) who's cloned in a clandestine experiment by his brilliant but twisted scientific mentor (Milland) with unintended consequences.
Interesting premise has Forster essentially playing dual roles (which he handles capably being the terrific actor he was), whilst pretty Barbeau plays his confused wife being unwittingly seduced by his increasingly brazen clone, whilst David Sheiner is another familiar face playing his academic nemesis.
Typical of the halcyon era for TV-made thrillers, well-paced, moody, atmospheric aesthetic and just as compelling as theatrical films. 'Medical science' horror movies were briefly in vogue (e.g. Coma, Embryo, Scalpel) at the time, of which DSOT is a neat little exponent.
Despite being well beneath his Hollywood legacy (though not as low as 'The Sea Serpent'), Milland makes anything more watchable and his presence here is quality casting that should reach a wider audience.
Director Trikonis has crafted a taut, scary thriller headlined by a high quality cast of distinction, and worthy of attention - that is, if you can locate it; I managed to find an ex-rental VHS copy on the Video Classics label many years ago, but it seems to be rather obscure.