I believe this is the second appearance of Rankin's team of psychic investigators, Sir John Rimmer, Dr Harney, and Danbury Collins. Working for the Ministry of Serendipity located under Mornington Crescent, which secretly runs the world, the three of them go to a Pacific island where an alien sprout monster is making a comeback. The alien, whose name is Dilbert Norris, landed on Earth centuries earlier and got humans to worship him as a god, but was trapped under the sea after the sinking of Mu. The main protagonist, however, is actually a guy called Porrig (actually Padraig, but nobody calls him that), someone who always manages to put his foot in his mouth. He also draws offensive comics that he doesn't understand why people aren't interested in, and even his parents don't particularly like him. He inherits a derelict bookstore from his uncle, the magician Apocalypso, and discovers a way to shift between alternate worlds by using harmonics. Accompanied by a dvergar named Rippington and his distant ancestor who can't die until he's returned a feather to an angel, he has to find a way to defeat Dilbert. There are a lot of the usual elements in Rankin novels here, including running gags, secret government conspiracies, monster attacks, sprouts, and a lazy and unpopular but imaginative hero. I understand the Kindle edition, which I read, was edited within the past few years by the author, who fixed some plot holes and cut some penis jokes.