Patron of the Moon + Simic Growth Chamber + Horizon Explorer

Patron of the Moon

Simic Growth Chamber

Horizon Explorer

How it works

1. Pay 1 to activate Patron of the Moon, putting Simic Growth Chamber from your hand onto the battlefield untapped due to Horizon Explorer.
2. When Simic Growth Chamber enters, it triggers.
3. Activate Simic Growth Chamber by tapping it, adding two mana.
4. Resolve Simic Growth Chamber's triggered ability, returning it from the battlefield to your hand.
5. Repeat.