Slipper Tarn is a pond in the middle of the woods in the National Trust Cragside estate. It is a good place for a visit on a windy day as it is so well sheltered by the trees. The black darters don't do much darting but spend much of their time resting beside the pond edge.
This couple spent more than 15 minutes eyeing each other up but nothing came of it while I was watching.
There were half a dozen or so male common hawkers on patrol but they never seem to rest so I didn't manage a photo. However, I did see two ovipositing females.