I MUST confess, I was fearing the worst. Catherine "Am I Bovvered?"' Tate as Doctor Who's time travelling companion just didn't sound right.

My reaction was partly influenced by her appearance in the 2006 Christmas episode which I found pretty tame.

And yet after Saturday's first episode I'm already coming round to the idea that it might prove an inspired bit of casting. True there were one of two expressions very familiar to watchers of the Catherine Tate Show, but on the whole the Beeb could be on to a winner.

As for the first episode as a whole, I reckon the producers are lulling us into a false sense of security with the cute little aliens being produced by some miracle diet pills.

Even Sarah Lancashire as the transatlantic super nanny was fairly benign as far as Doctor Who baddies go.

In fact the whole episode was so unscary that I dread to think how far behind the sofa we're going to be forced to hide once the real nasties start to appear. David Tennant has slotted straight back into his wild-haired, slightly bemused Doctor expression.

And already there was one stroke on genius - the appearance (and disappearance) of Rose Tyler at the end.

Now what was that all about?

No doubt time will tell.