Macavity: the mystery cat

Macavity's a Mystery Cat: he's called the Hidden Paw—
For he's the master criminal who can defy the Law.
He's the bafflement of Scotland Yard, the Flying Squad's despair:
For when they reach the scene of crime—Macavity's not there!

(TS Eliot)

Of course, it's somewhat unfair when an epithet like this sticks to someone with the power, authority and dignity (*snigger*) of the office of Prime Minister of the United Kingdom, because it means that even if he genuinely wasn't involved, it's impossible for him credibly to deny it. However, it's stuck, as Martin Kettle wrote even in May last year, and stuck because, as with all good clichés,

it's essentially true. No one in the Blair cabinet has had greater power and authority for the last ten years than the Chancellor. But when something goes wrong, just like Old Possum's monster of depravity, Brown is never there to take the rap.

So when he denies all knowledge of the arrest of Damian Green, the question isn't, Is he telling the truth, but rather, Will anyone believe him?