But what's a leyline? In Magic they're hidden lines of mystical force that grant great power to mages who know their secret locations. The art of each card depicts a wizard, somewhere in one of Ravnica's district courtyards or back alleys, taking advantage of this cryptic lore to unlock this power.
Since these pieces were assigned to five (well, actually six) different artists, we get the treat of seeing how each artist interpreted the scene. Take a look. Note how each represented the idea of a nexus of magical lines in a state of activate. Note how the look of the wizard -- and the perspective on the figure -- changes from piece to piece. Note the amount of Ravnican architecture shown off in the background of each scene.
Leyline of the Meek art by Mark Zug
In the white leyline, might there be the suggestion that the wizard uses his staff to not only unlock, but somehow deliver the leyline's power elsewhere? Perhaps to a distant brood of Selesnyan saprolings?
Leyline of Singularity art by Zoltan Boros & Gabor Szikszai
The art of the blue leyline clearly implies the power of the individual -- there's no power-sharing going on here. The mage stands alone in a relatively large city square -- have squads of newly-legendary Wojek Embermages and Watchwolf recently vanished in pairs?
Leyline of the Void art by Adam Rex
The rush of energy in the black leyline is evident -- and it's not a positive energy: check out the nixing gesture the mage makes with his hands, and the ring of spirits around him. These leylines appear to intersect at a landmark -- might previous generations of Golgari or Orzhov guild-members have used its power before?
Leyline of Lightning art by Paolo Parente
Check out this back-alley red mage charging up his reserves of lightning. Is this node of electric force a natural phenomenon of the plane of Ravnica, or is he leeching energy from nearby Izzet foundries?
Leyline of Lifeforce art by Kev Walker
The green leyline overflows with verdant energy -- too much of it, in fact, for some blue mage to interrupt its flow. Interestingly, one of the lines seems to flow through a nearby tree -- do these leylines form a network connecting all of Ravnica's precious few patches of natural growth?