The Last Aerie is the second book in Brian Lumley's Vampire World trilogy. In the last book, the sons of Harry Keogh in Starside had gone to war. Nestor had become Vamphyri and Nathan had fallen victim to his brother's rage and been thrown into the portal between Starside and Earth. This book takes up with Nathan coming through the portal into Perchorsck and being captured by the Russians, who are planning on attacking Starside. Luckily, Harry's old friends in E-Branch find out and come to the rescue, taking him to London and showing him how to better use his Necroscopic powers. In Starside, Nestor plots to find a way to destroy his brother once and for all.
Put simply, this is a filler book and it does it's job well. In this book, we get to catch up with E-Branch and see what's been happening in the years since the death of Harry Keogh. And on the other end, we get to follow more of Nestor's story on how he became a vampire and a powerful one, at that. The rest of the book is a bridge between the final confrontation where we get to see Nathan learning how to interact with the dead and how to use the Mobius Continuum. Lumley is still at his disturbing best and I don't care how many weird horror books you've read, his stuff will still creep you out. A good read.