Courier of Causality

I am an ordinary courier, and one day I started delivering to non-existent addresses. The recipient is a missing, deceased, or forgotten person. Every time a task is completed, reality is quietly rewritten. Some make up for regrets, some repay karma, and some regain a new life. I thought it was just delivery, but I found myself the only rule executor in the city. The secret of the wishing pool, the disappearing building, and the late-night receipt... all bizarre events point to the same truth. This time, it's my turn.