Board Thread:The Reference Desk/@comment-5545417-20131116122722/@comment-188432-20131130191851

Ultimately though, Seven says that he does remember events, and indeed has enough knowledge of the past to arrange for Five to be knocked out because he remembers having been knocked out. Cold Fusion is really, ultimately, about Five being manipulated by Seven. [The fifth Doctor said:] ‘You do remember. You’ve remembered all along.’

The Doctor smiled enigmatically and tapped the side of his nose.

At the pre-arranged signal, Forrester knocked out the fifth Doctor with a swift blow to the back of the head. The seventh Doctor bent over his past self, but rubbed his own skull. ‘A palpable hit,’ he said. Cwej was looking bewildered.

‘Sorry,’ Roz said, biting her lip, ‘I wasn’t sure whether you still wanted me to –’

‘Not at all,’ the Doctor replied quickly. ‘I don’t remember feeling a thing.’ He looked down at his prone former self. ‘I think we’d better leave, though.’