Harry and Hermione Pt. III — Finishing their Sixth Year and Into the Summer is the final installment of the trilogy. The Prequel is Harry and Hermione — Their Sixth Year. The book starts in January and finishes in August. There is also an Epilogue for the year 2004. DrT writes:
A strange dance, Dursleys, Grangers, vampires, elves, and Voldemort — Harry and Hermione have a lot on their mind this spring and summer, especially when the Dark Lord issues a challenge Harry cannot ignore.
The vampire Cassandra is introduced. There is an attack on the school on valentines day – the students have masked ball while the school is breached. On easter Grimauld Place is attaced. Free elfs become an issue thereafter. In the summer holyday there is some training for the final show down on 20th august. Voldemort dies and Harry is no longer alive.
The story can be found online at Schnoogle.
I also made a PDF out of the ten chapters.