What is a short summary of the story, Skinder's Veil, from the collection, White Cat, Black Dog: Stories?

In Skinder's Veil, Andy Sims, a struggling PhD student in Philadelphia, agrees to house-sit in rural Vermont for his friend Hannah. He encounters strange rules upon arrival, including never letting Skinder, a person who looks just like Andy, enter the house. Over the three weeks, different individuals, including Rose White and Harlan Coben, follow the rules and enter the house. Rose Red, who denies having a sister, arrives and shares hallucinogenic mushrooms with Andy while telling stories involving Death. At the end of his house-sitting, Andy returns home, completes his dissertation, and secures a job. Years later, he experiences a strange encounter near Skinder's house in Vermont.