Nick Cave has shared the secrets of his friendship with long-time collaborator Warren Ellis on his latest entry in The Red Hand Files.The pair have worked together across various projects since 1993, including Nick Cave & The Bad Seeds and Grinderman.After being asked by multiple fans about their friendship and songwriting, Cave shared his theory that there are three levels of friendship – essentially those defined by “a shared experience,” “someone who has your back,” and ones who can “bring