Retreat to Coralhelm, Sakura-Tribe Scout, and Dimir Aqueduct

Prerequisites

• Retreat to Coralhelm on the battlefield
• Sakura-Tribe Scout on the battlefield
• Dimir Aqueduct in hand
• Sakura-Tribe Scout does not have summoning sickness

Steps

1. Activate Sakura-Tribe Scout 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 Sakura-Tribe Scout
5. Repeat

Results

• Infinite landfall triggers