Scenario:
- I put 9 black mana into my mana pool
- I cast Massacre Wurm
- I cast Sudden Spoiling
- I pass priority to my opponent
Sudden Spoiling has Split Second, which means that says players cannot cast spells or activate non-mana abilities while it is on the stack:
Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
After Sudden Spoiling resolves, will players be able to interact with Massacre Wurm on the stack?