Since Team Flash has been shedding team members this season, and with Cisco helping Wells, Barry and Caitlin went out in search of Amunet to get her assistance in defeating The Thinker, with Caitlin having an ulterior motive to use the villain’s splicer tech to bring Killer Frost back.
It turns out it wasn’t the splicer tech that helped Caitlin gain control of Killer Frost, since it didn’t work on her at all.
Rather, Caitlin was her own cure in that respect, just by believing in the placebo effect.
Of course, there was a mess involving the cloudy-eyed Norvok having robbed Amunet, but that was something of a Macguffin, since Amunet had been lying to her all this time.