Basalt Monolith, Ensoul Artifact, and Heartstone

Prerequisites

• Basalt Monolith on the battlefield
• Ensoul Artifact on the battlefield
• Heartstone on the battlefield

Steps

1. Activate Basalt Monolith's first ability by tapping it, adding
2. Activate Basalt Monolith's second ability by paying , untapping it
3. Repeat

Results

• Infinite colorless mana