Underdark Rift is a uncommon Land card from Forgotten Realms Commander (AFC), collector number 62. Current market price: $0.54, TCGplayer market prices via Scryfall.
{T}: Add {C}. {5}, {T}, Exile this land: Roll a d10. Put target artifact, creature, or planeswalker into its owner's library just beneath the top X cards of that library, where X is the result. Activate only as a sorcery.