Shadowy Backstreet is a rare Land — Plains Swamp card from Murders at Karlov Manor Promos (PMKM), collector number 268p. Current market price: $11.40 (foil $13.37), TCGplayer market prices via Scryfall.
({T}: Add {W} or {B}.) This land enters tapped. When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)