Behind the techno beats and disco lights of the Fifty Beach Club, a temple of hedonism on the banks of the Dnieper River, a more low-key theatre is being played out: that of the shadow war waged by Western intelligence in Kyiv.

The venue, known for attracting models, mercenaries, crypto millionaires and tattooed veterans of the Ukrainian International Legion, has been a discreet meeting place for spies from across Europe, mainly French, for over a year.

Set in the open air on the wooded heights of