Lupin sat down, and sighed; Malfoy had escaped the Order again.  

"We'll have no luck following him; I know of ten different ways to get
past the Apparition Barrier without being seen." 

Snape looked querulously at him, "Ten?"

"The Staff-room 'back door', the Chamber of Secrets, ..."

"...The Room of Requirement..." interrupted Tonks.

"...oh, yes, make that eleven then, and isn't the Headmaster's Office
supposed to have an exit in the roof?" Lupin continued.

"That's a myth," Snape replied quickly.  "The Whomping Willow and
Honeydukes I know about, but what about the other six?" 

Lupin tapped his nose knowingly, and grinned.