As they plan their infiltration, the wizard just sits tightly inside his bedroom bored to dead while sipping his tea. David advises the two friends he had not to spill any secret plan to the wizard because he's still somewhat contracted with Edelweiss Country. If so, any pieces of information that leaked to him wouldn't be safe.
Elder Kars might have some tricks in his sleeves to extract the information out from Petrie. Crow agrees with his line of thinking, but the sole problem lies in David's plan to infiltrate the underground prison. Even with Min Soo helping him, getting him in wouldn't be that easy. Not to mention, getting out could be impossible.
Edelweiss's most famous prison, the Thorn of Evil is a basement prison where they lock away all trespassers and criminals in one large underground prison. Divided by level, David is certain that his traveling mates should be located at the earliest level since Elder Kars considered them as trespassers.