Harley Quin is an enigma. Even his friend Mr Satterthwaite is unable to understand how the man seems to appear and disappear almost like a trick of the light - and when he does appear it's usually in the sparkle of sunshine, or surrounded by a spectrum of coloured light pouring through a stained glass window...

In fact, the only consistent thing about the Mysterious Mr Quin is that his presence is always a harbinger of love ... or death.