1 : truthful, veracious
2 : not illusory : genuine
I am feeling particularly prosaic this morning, so I'm going to leave you with my favorite paradox concerning the nature of VERIDICALITY. I get Sarah's logic, I believe she's correct, BUT what if the blue guy was lying when he initially exclaimed, "one of us always tells the truth, and one of us always lies." What if they are both liars. Would that change the logic? It almost doesn't even matter because we all know David Bowie and his glorious package are ultimately in control of Sarah's fate anyway.
In her defense, I'm impressed. If I were sixteen and faced with that riddle I would have probably cried or committed suicide—depending on the stakes.