>> the reporter who knew princess diana the best. >> the one thing she wouldn't want to do of course is upstage the bride or would she? >> and a sea of other guests. a bit of royal sparkle. >> i was just ryie intrying to impress you. >> this is a special edition of "piers morgan tonight." i'm outside buckingham palace. less than 48 hours to go to the big wedding. the crowds beginning to flock all over london for the big day. i've been talking about two royal experts. two ladies who have written very successful books. katie nicole, who wrote william and harry, behind the palace walls. i'm joined by an historian, best selling author of "the red queen." which is today on charts. everybody's going royal crazy here. let me bring you in first. we're less than two days away.