WHOSENTAMBERLEEANANONYMOUSLETTER?Everyonelovesthenewteacher,Mr.Merlin.Mr.Merlinusedtobeaspy,andheknowsallaboutsecretcodesandthestrangeandgrosswaysthepolicesolvemysteries.Nowthere’samysteryintheirveryownclass--someonesentAmberLeeJohnsonananonymousletter.NoelleandToddwanttosolvethemysterybeforeanyoneelse.ButfirsttheyhavetofigureoutMr.Merlin’sclues.Howcanabunchofenvelopestellthemwhosenttheletter?
