When Dimir Aqueduct enters the battlefield, it, The Necrobloom, and Kodama of the East Tree trigger.
Resolve the Kodama of the East Tree trigger, choosing not to put anything from your hand onto the battlefield.
Resolve the Dimir Aqueduct trigger, returning it from the battlefield to your hand.
Resolve the The Necrobloom trigger, creating a token.
When the token enters the battlefield, Kodama triggers, putting Dimir Aqueduct from your hand onto the battlefield.
When Dimir Aqueduct enters the battlefield, it and The Necrobloom trigger.
Repeat from step 4.
This elegant loop turns a simple bounce land into a self-sustaining engine by bridging land mechanics with creature tokens. Every time Dimir Aqueduct enters the battlefield, its own bounce trigger returns it to your hand while The Necrobloom reliably rewards each land drop by spawning a fresh creature token. That token's entry triggers Kodama of the East Tree, allowing you to instantly drop Dimir Aqueduct right back onto the battlefield from your hand to restart the entire sequence.