Well, then, this current adaptation does what virtually every previous one has done. It cuts the second generation, artificially inflates the Cathy-Heathcliff relationship (which takes up surprisingly little of the novel), and makes it doomily but conventionally romantic/sexual (something that was essentially invented for Hollywood tastes by the 1939 Olivier/Merle Oberon adaptation).
In the novel teenage Cathy, after she’s got to know the Lintons, is frequently bored by Heathcliff’s company (she says sitting with him is like being with a baby or a dumb person), and to view him as a prospective husband, even in rejecting him, doesn’t seem to have occurred to her until Edgar proposes, when she doesn’t see her relationship with H as being at all changed by her prospective marriage, says that Edgar must learn to tolerate him, and doesn’t think H would understand what ‘being in love’ meant.
When Heathcliff returns after her marriage, she is delighted to see him, but there’s no evidence at all she regrets her choice of Edgar, or that she’s been in love with H all along — she just wants him to be able to visit her at Thrushcross Grange. She always voluntarily takes Isabella with her when they meet for a walk. There’s no undercurrent of sexual longing or possessiveness when Isabella’s attraction to H becomes evident. She’s primarily irritated by the Isabella situation because it infuriates Edgar and prevents her from ‘keeping Heathcliff as my friend’, which appears to be all she wants. H says he’s marrying Isabella in part to revenge himself on Cathy for her ill treatment of him. They kiss only on Cathy’s deathbed, when she’s heavily pregnant and will die later that night (when she also pulls out a handful of his hair), and it seems to be more about death separating them than sexual desire. There’s no evidence they ever have sex. And far from haunting him out of love, it’s Lockwood, a slightly dopey stranger, that ghost C appears to. She only haunts Heathcliff to stop him disinheriting her daughter by making him starve himself to death.
It’s a lot weirder than any ‘doomed romance’ adaptation has ever made it.