The Alzheimer Incident

Setting: 1987 – six years after the fall of Voldemort.
When it becomes clear that Albus Dumbledore is no longer capable of fulfilling his duties, it falls to Severus to take care of the orphaned boy Harry Potter. While he had initially assumed it would amount to nothing more than a visit every month or two, it soon becomes apparent that far more things have gone wrong over the past years than anyone had realized.