Intruder Alarm, Stonybrook Schoolmaster, and Drowner of Secrets

Prerequisites

• Intruder Alarm on the battlefield
• Stonybrook Schoolmaster on the battlefield
• Drowner of Secrets on the battlefield

Steps

1. Activate Drowner of Secrets by tapping Stonybrook Schoolmaster
2. Stonybrook Schoolmaster triggers, creating a 1/1 Merfolk Wizard creature token
3. When the Merfolk Wizard enters the battlefield, Intruder Alarm triggers, untapping all creatures
4. Resolve the Drowner of Secrets ability, causing a player to mill a card
5. Repeat

Results

• Infinite ETB
• Infinite mill
• Infinite self-mill
• Infinite creature tokens
• Infinite untap of all creatures
• Infinite mana creatures you control can produce