Cast Unearth by paying , targeting any applicable target.
Holding priority, cast Dualcaster Mage by paying 1.
When Dualcaster Mage enters, it triggers, targeting Unearth.
Holding priority, activate Woe Strider by sacrificing Dualcaster Mage.
Resolve the Dualcaster Mage trigger, copying Unearth, with the copy targeting Dualcaster Mage.
Resolve the Unearth copy, returning Dualcaster Mage from your graveyard to the battlefield.
Repeat from step 3.
This clever loop hinges on Unearth returning Dualcaster Mage to the battlefield, where its enter-the-battlefield trigger targets the original Unearth to start an endless duplication cycle. To break the symmetry and fuel the combo, Woe Strider steps in as the ultimate sacrifice outlet, letting you pitch Dualcaster Mage to its teeth while smoothing your draws with repeatable scry triggers. Because Woe Strider brings along a Goat token on entry and can later escape from the graveyard, it rounds out the engine with a reliable source of early fodder to keep your sacrificial machinery running smoothly.