The Incest Plague

Your name is John Hamilton. You were born in a family with six children including you:

• The eldest sister Diana, who was three year older than you.
• Twin sister Alicia and Beth, who were one year older than you.
• Twin sister Olivia and Helen, who were two years younger than you.

Being a single mom with 6 children didn't give your mother, Mrs. Minerva Hamilton, any financial problem since she had a high position in Abrellum Corporation, the largest medical company in the world, the producer of 60% healthcare product and the supplier of 80% medicine. Your three older sisters also worked to this company.

You just graduated from a famous university and your application to Abrellum Corp was accepted immediately.

Your work went smoothly for half a year. Until one day...