Retreat to Coralhelm, Scaled Herbalist, and Dimir Aqueduct

Prerequisites

• Retreat to Coralhelm on the battlefield
• Scaled Herbalist on the battlefield
• Dimir Aqueduct in hand
• Scaled Herbalist does not have summoning sickness

Steps

1. Activate Scaled Herbalist by tapping it, putting Dimir Aqueduct from your hand onto the battlefield
2. Dimir Aqueduct enters the battlefield, triggering itself and Retreat to Coralhelm
3. Resolve the Dimir Aqueduct trigger, returning itself from the battlefield to your hand
4. Resolve the Retreat to Coralhelm trigger, untapping Scaled Herbalist
5. Repeat

Results

• Infinite landfall triggers