This story was staying in the fine but not impressive range that the last few Doom Coalition stories have been inhabiting until a surprising fun and exciting plot twist right at the end. The Doctor, Liv, and Helen investigate the destroyed Voord homeworld and find an antique TARDIS spilling out. Landing, it's a standard story with insane servants who are likely Time Lords in some bizarre facility where people are being tortured. We've heard a lot of those recently. The whole time they are vaguely confusing throwbacks about Caleera, the main prisoner, back on Gallifrey. She seems to be Time Lord Helen, a woman not respected in Time Lord society...until it turns out she's actually an evil villain who is destroying planets for fun. It was an unexpected twist and I can only assume her love is the Eleven, but we'll wait and see. Hoping this twist gives the series a bit more juice.