I enjoyed it very much. It's a psychological drama and Judi Dench and Cate Blanchett are amazing throughout. The tension, the "what's going to happen next" wavers a little in the middle, but there's a worthwhile climax and a slightly creepy but satisfying ending.
Other parts played by:
Tom Georgeson (Ted Mawson) - Pymar in Need to Know and Reed in In the Public Interest
Philip Davis (Brian Bangs) - Billy Turner in Old Dog New Tricks
Jill Baker (Sheba’s Mother) - Amanda in Hijack
Afterwards, an OK meal and a couple of drinks at 'The Red Cow' in Penrith.