This book is the third in the Capital Mysteries series. K.C. and her friend Marshal go to dinner with the president and find out that someone claims to be in heir to James Smithson. (The person that built the smithsonion institution.) When Marshal sugests they compare DNA to see if the person is related to James Smithson, The Heir Smiles, what is he up to??? Is he really an heir to James Smithson?? Or is he a fake?? Find out in Skeleton in the Smithsonion!! I reccomend this book to kids 5 and up.