11 Times Doctor Who Stupidly Spoiled Its Own Secrets

4. Catherine Tate Revealed David Tennant Was Leaving... A Year Before It Was Actually Announced

The Secret: After Series 4 of Doctor Who managed to break ratings records and catapult the show into new levels of mainstream success, the BBC decided to take the next logical step by cutting down its production and churning out 4 sporadic 'specials' throughout 2009 as opposed to the full 13 episode run that its fans had grown accustomed to. Um. It probably made sense at the time. One of the hot topics that dominated discussions was what the 'gap year' would mean for David Tennant's fate as the Tenth Doctor. It seemingly made sense for him to bow out at the end of the specials but the BBC were naturally keeping his future in the TARDIS close to their chests... How It Was Spoiled: By Catherine Tate and her big old mouth! It wasn't her fault, of course, as she somehow (???) didn't realise that David Tennant's future in the role was being closely guarded as one of the biggest secrets in TV history. The Donna Noble actress casually let slip - during a 2007 radio interview - that he'd be stepping down as the titular Time Lord after the 2009 specials, which the BBC promptly denied before eventually confirming it almost a year later. Needless to say, Catherine hasn't taken part in any Doctor Who interviews since.