Detection Tower is a rare Land card from Core Set 2019 (M19), collector number 249. Current market price: $3.28 (foil $4.33), TCGplayer market prices via Scryfall.
{T}: Add {C}. {1}, {T}: Until end of turn, your opponents and creatures your opponents control with hexproof can be the targets of spells and abilities you control as though they didn't have hexproof.