It really should be, but Ray's not really ready to deliver his 'welcome to milliways' speech with a side-order of philiotic doorway lessons these days.

"Yeh, though it won't work on every door. You have to hold the coaster in your hand and think about Milliways really hard when you open a door." A pause. "Out-of-the way doors work best. And ordinary doors work best on Tuesdays for some reason."