What does the inspector want from Anna?

Mission Berlin 01 – Rude Awakening

Anna's mission is to save Germany from a disaster. She has to keep the secret, solve the puzzle, and watch out for men on motorcycles. She's got 130 minutes. But where's her first clue?

Anna wakes up in room 14 ... Zimmer vierzehn, in a hotel in Germany with a police superintendent ... Kommissar ... on his way to her room. Superintendent Ogur introduces himself and mentions the murder of a guest in room 40 ... Zimmer vierzig. On the bathroom mirror he notices the phrase, "In der Teilung liegt die Lösung; folge der Musik". Anna goes down to answer the superintendent's questions. But what does the phrase mean?