Shadowy geniuses whispering, Rasputinlike, into the ears of our elected politicians under a cloak of secrecy, or a crucial but undervalued cog in the machinery of government? Or just a rag-tag band of weirdos and misfits?Despite the acres of speculation devoted to special advisers in recent years, from Alastair Campbell to Dominic Cummings, their role is much misunderstood. Who are the people Piers Morgan once called these miserable little creatures and just how much influence do they have?