Article continues below advertisementPrince Harry is facing fresh ridicule from royal insiders who claim he and Meghan Markle are viewed inside palace circles as "sleeper cells" poised to undermine - and ultimately replace - Prince William and Princess Kate. Harry's recent brief reunion with King Charles during a return to Britain has triggered what one senior aide called a "wave of deep unease" in royal circles about the impact his and his wife's return to the folds of The Firm may have on the institution.