"Herogasm" is the name of an orgy the supes attend every year when they tell the rest of the world that they're joining forces to fight off a space alien threat far away. They get together on a remote tropical island and it's "Caligula" but more graphic.
There's not much more to the story - Homelander's planning something, Vought American continue their plan for world domination, the Boys find some more backstory to their version of 9/11 that wasn't elaborated on in "Good for the Soul". But it's not enough for a full book.
I'm not a prude by any stretch but there's far too much gratuitous porn. Supes doing it with hookers, doing drugs, this goes on for pages and pages. If I wanted porn I'd have some, but when I pick up a comic book, especially one as good as this series is, I expect something more, and sadly, this book has none of the interest of the previous 4.
John McCrea's not a terrible artist but Darick Robertson is a better one and his presence is definitely missed in this book. Hopefully the hints set up in "Herogasm" will make for a much more interesting 6th book. This book is definitely missable and adds nothing to the overall story arch of this series.