10 cards where the cards are duals lands that are 'fast'

Blackcleave Cliffs (Duskmourn: House of Horror Commander #263)
Blooming Marsh (Outlaws of Thunder Junction #266)
Botanical Sanctum (Outlaws of Thunder Junction #267)
Concealed Courtyard (Outlaws of Thunder Junction #268)
Copperline Gorge (Phyrexia: All Will Be One #249)
Darkslick Shores (Outlaws of Thunder Junction Commander #281)
Inspiring Vantage (Outlaws of Thunder Junction #269)
Razorverge Thicket (Phyrexia: All Will Be One #257)
Seachrome Coast (Phyrexia: All Will Be One #258)
Spirebluff Canal (Outlaws of Thunder Junction #270)

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