A queenly manipulatress wants her cousin to seduce an innocent whom her husband intends to take as his courtesan.
If Untold Scandal's tale of seduction, cynicism and unexpected romance is familiar, that's because it's an exact remake of Dangerous Liaisons, transposing the libertinage and letter-writing from 18th-century France to Korea. The major difference is that the queenly manipulatress (Jeon) wants her cousin (Bae) to seduce not an underage bride, but an innocent (Lee) her husband intends to take as his courtesan, while the ridiculously chaste heroine (Lee Mi-suk) is an unusual Korean Catholic.
Otherwise, it's the same story: Bae is slightly too dispassionate a seducer, but the three women are remarkable, at once extraordinarily beautiful and unsettlingly intense. It's mostly talk, with decent costumes and sets, but there are some great cinematic bursts, such as Bae fending off an assassin with a fan and the heroine's fate on an icy lake.
This Korean adaptation of Dangerous Liasons is very 'talky', but the three lead females are excellent, as are the costumes and sets.