"To be... uh, [i]sneaky[/i], why else?" Siobhan said with pride-worthy sass for a Gryffindor.

When they discovered the landing to be empty, Siobhan's eyes narrowed in suspicion. Poking her head out, she looked left then right to ensure the gang of Slytherins weren't waiting around the corner having already seen them, but they were nowhere to be seen. "They're definitely around here somewhere," she said resolutely. "They can't have just disappeared into thin air." 

Courageously (or stupidly) she came fully out into the corridor -- a Hufflepuff wasn't anything to be frightened of, for sure -- and began sleuthing around... or as close to that as an eleven year old could be. "People don't just [i]vanish[/i]!"