This clever loop transforms a simple land drop into an engine of exponential growth, starting when you play Gruul Turf. Because Horizon Explorer ensures your lands enter the battlefield untapped, Gruul Turf triggers its own return-to-hand clause alongside Springheart Nantuko's landfall ability, leaving a window to tap the land for mana to pay for the copy effect. This lets you churn out a token copy of Icetill Explorer, whose static ability grants you the extra land plays needed to redeploy Gruul Turf over and over again. As the cycle repeats, the steady stream of landfall triggers not only fuels itself but also leverages Icetill Explorer's mill ability to fill your graveyard while flooding the board with infinite creature tokens.