Concernedabouthisfriend'scocaineuse,Dr.WatsontricksSherlockHolmesintotravellingtoVienna,whereHolmesentersthecareofSigmundFreud.FreudattemtstosolvethemysteriesofHolmes'subconscious,whileHolmesdevoteshimselftosolvingamysteryinvolvingthekidnappingofLolaDeveraux.