Written by Steven Moffat
Directed by Douglas Mackinnon
Bit of a strange one for me. The diamond/Hydroflax plot was poorly thought out and not very engaging.
Also Hydroflax, Nardole and Ramone were wasted as characters.
On the other hand, Twelve and River had chemistry in spades and Capaldi/Kingston were a joy to watch.
It was though the Darillium stuff that was the episode's highlight and should've had the bigger focus.
I guess for a final episode for River, it should've felt more like an event episode, 7/10