Given the task definition and input, reply with output. 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) Water from the surface seeps below the soil (2) The water comes into contact with the rock below (3) The rock over the years carves through the rock (4) The space in the rock becomes larger and forms into a cave
Where does the following step fit into the given list of steps: As more rather rushes through the cave becomes a cavern.
After step 4.