Heart and Club.
(Agrotis clavis)

This one needed a closer look and further consultation to identify it.

Information:
It was explained to me thus: "The markings look like they've been drawn in ink, but then got wet and run as if the moth were made of blotting paper" and it has "'double' cross-lines before & after the oval and kidney" - which fits the bill pretty well for this moth.
Fore-wing length: 14-18mm. They can be confused with Turnip moth, Heart and Dart, Crescent Dart or Great Dart. They fly June-August over open and dry habitats such as some gardens, woodland rides, chalky downs and coastal sand-dunes. They can be seen mainly in Southern Britain.