From acclaimed French filmmaker François Ozon (_Sous le sable_; _8 femmes_; _Frantz_), _L'amant double_ [_Double Lover_] functions as an exploration of sexual obsession, a dreamlike mystery reminiscent of Neil Jordan’s _In Dreams_, and also incorporates elements of a conventional thriller—though more focused on “whoisit” than “whodunnit.” "Freely adapted" from Joyce Carol Oates's 1987 novel _Lives of the Twins_ (writ…