Each of the other answers contains the name of one of the seven given characters: heADLinERs - ADLER WhATS yOur poisoN - WATSON MORtAl wouNds - MORAN LoudEST RoADiEs - LESTRADE MYopiC pROFiTeer - MYCROFT MinORIty pARTY - MORIARTY The unmatched character is the mastermind: MRS. HUDSON