15 cards where the illustration contains “edge-of-plane”

Catastrophe (Urza's Saga #6)
Drifting Meadow (Commander 2013 #285)
Drifting Meadow (Urza's Saga #320)
Forbidding Watchtower (Urza's Legacy #140)
Peace and Quiet (Urza's Legacy #17)
Plains (Duel Decks Anthology: Divine vs. Demonic #26)
Plains (Duel Decks Anthology: Divine vs. Demonic #27)
Plains (Urza's Saga #333)
Plains (Urza's Saga #334)
Primal Beyond (Morningtide #149)
Rath's Edge (Nemesis #142)
Sanctum of Serra (Planechase Planes #32)
Serra's Sanctum (Urza's Saga #325)
Shimmering Barrier (Urza's Saga #50)
Voyage's End (Theros #73)

The message was clear to Sorin—time to search for something else.