Lady Tenia din Aedrider, the strongest known being, issued a command to Lucius. Though she verbalized no threat, every fiber of Lucius's being inferred that to be her intention, should he refuse.
While Lucius himself would be the first to admit he was headstrong, he was not stupid. Lady Tenia's request would be fulfilled without fail. What did surprise him was that the human scent he picked up belonged to Lady Voltara al Famyn. He found it strange she would be present in the elf palace and stranger still that she needed something from him.
Along with all of that, the place he needed to go was Stark Academy. What would they need from him there? Surely, they didn't need him to be a teacher.
Magic Castle Bonus Chapter 3, Thank you, DarkElven6!!