HauntedbythememoryofWalterHolderlin,asoldierhekilledduringWorldWarI,FrenchmusicianPaulRenard(PhillipsHolmes)confessestoapriest(FrankSheridan),whograntshimabsolution.Usingtheaddressonaletterhefoundonthedeadman'sbody,PaulthentravelstoGermanytofindhisfamily. Asanti-FrenchsentimentcontinuestopermeateGermany,Dr.Holderlin(LionelBarrymore)initiallyrefusestowelcomePaulintohishome,butchangeshismindwhenhisson'sfiancéeElsaidentifieshimasthemanwhohasbeenleavingflowersonWalter'sgrave.Ratherthanrevealtherealconnectionbetweenthem,PaultellstheHolderlinfamilyhewasafriendoftheirson,whoattendedthesamemusicalconservatoryhedid. Althoughthehostiletownspeopleandlocalgossipsdisapprove,theHolderlinsbefriendPaul,whofindshimselffallinginlovewithElsa(NancyCarroll).WhensheshowsPaulherformerfiancé'sbedroom,hebecomesdistraughtandtellsherthetruth.SheconvinceshimnottoconfesstoWalter'sparents,whohaveembracedhimastheirsecondson,andPaulagreestoforegoeasinghisconscienceandstayswithhisadoptedfamily.Dr.HolderlinpresentsWalter'sviolintoPaul,whoplaysitwhileElsaaccompanieshimonthepiano. Thefilm'soriginaltitle,TheManIKilled,waschangedtoTheFifthCommandmenttoavoidgivingwrongimpressionsinthemindsofthepublicaboutthecharacterofthestory.ItultimatelywasreleasedasBrokenLullaby.