That's all Ralph needs to hear. His ear slips back through the ducts as he formulates a quick plan..

One cocktail napkin and an ink pen later, he's concocted a short note to Piper : 'Keep stalling, I will take care of the bombs!' and slipped it onto a chair near Hartley where a table will block the Joker's line of sight.

And with that, he moves along the floor, towards the basement access.