I control Debtors' Knell. There are no creatures in graveyards. I begin my upkeep.

What happens?

1. It does not trigger at all.
   
2. It triggers, but I can't put the trigger on the stack because there is no legal target.
   
3. It triggers, I put the trigger on the stack, and then the trigger is immediately taken off the stack again because it “fizzles” due to no legal target.
   
4. Other?
   

(I need to know because reasons.) Thanks!

The ability triggers and is put onto the stack, but since you cannot choose a legal target for it, the ability is then removed from the stack and the game moves on.

This isn't quite “fizzling” in the normal sense, since “fizzling” is generally used to mean being countered on resolution for having no legal targets, which isn't what's happening here, but it's the same general idea.

Edited Callum Milne (Dec. 29, 2014 12:49:48 PM)