Given a list of steps and an additional step, determine where the step fits into the original list of steps. A correct answer, correctly places the given step into the set of steps so that it creates a new plausible set of steps. Output must be formatted as 'After step n', where n is the step number after which the given additional step is to be inserted.

Steps: (1) Blood carried into kidney by the renal artery (2) Nephrons in the kidney filter the blood (3) Become urine (4) Ureters carry urine out of the kidneys.  
Where does the following step fit into the given list of steps: The waste that is filtered out mixes with water 
 After step 2. 