The only problem: the big cliffhanger ending of last week's episode implied Zilpha was going to do exactly that. In case you forgot, we last saw Zilpha standing over her dresser and pulling out the eventual murder weapon before putting it right back. When a death is telegraphed so clearly, it's up the the writers -- in this case, Steven Knight and Hardy's father, Chips -- to provide a narrative twist to create suspense. They didn't do that. Instead, we got a few scenes of her apparently working up the courage to do it, which might be realistic, but it makes for dramatically frustrating TV.
At the very least, this means that Zilpha is now free to have non-psychic sex with her half-brother. But, again, even that ends up getting disrupted. After she arrives soaking wet at Delaney's house, where he is already rocking his signature no-pants look, he behaves in a chilly manner, suddenly playing hard-to-get after weeks of casting suggestive glances her way. Later, when the two actually do hook up, Delaney has a vision of his mother drowning him, freaks out, and chokes Zilpha mid-coitus. It's all pretty disturbing. One thing is clear: these two need to see a couple's counselor.