Heartstone, Basalt Monolith, and Karn's Touch

Prerequisites

• Heartstone on the battlefield
• Basalt Monolith on the battlefield
• Karn's Touch in hand
• undefined available

Steps

1. Cast Karn's Touch by paying , targeting Basalt Monolith
2. Activate Basalt Monolith's first ability by tapping it, adding
3. Activate Basalt's Monolith's last ability by paying , untapping it
4. Repeat

Results

• Infinite colorless mana