Play Simic Growth Chamber.
Simic Growth Chamber enters the battlefield, triggering itself and Amulet of Vigor.
Resolve the Amulet of Vigor trigger, untapping Simic Growth Chamber.
Activate Simic Growth Chamber by tapping it, adding {G}{U}.
Resolve the Simic Growth Chamber trigger from step 2, returning itself to your hand from the battlefield.
Activate Gretchen Titchwillow by paying {G}{U}, causing you to draw a card and put Simic Growth Chamber from your hand onto the battlefield.
Repeat from step 2.

Infinite card draw

Infinite draw triggers

Near-infinite landfall triggers

Gretchen Titchwillow

Simic Growth Chamber

Amulet of Vigor

Training Grounds

Biomancer's Familiar

Play Simic Growth Chamber.
Simic Growth Chamber enters the battlefield untapped due to Archelos, triggering itself.
Holding priority, activate Simic Growth Chamber by tapping it, adding {G}{U}.
Resolve the Simic Growth Chamber trigger from step 2, returning itself to your hand from the battlefield.
Activate Gretchen Titchwillow by paying {G}{U}, causing you to draw a card and put Simic Growth Chamber from your hand onto the battlefield.
Repeat from step 2.

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