Board Thread:The Panopticon/@comment-3999524-20141211184047/@comment-5253713-20141212043610

From Legacy:

Long hours passed. The information started to come through, and as he read it the Doctor paused.

Tersurus...

And then the track of an unshielded TARDIS, which then reshielded itself and left the dismal planet.

His fingers hovered over the controls, and didn't descend.

Tersurus...

He aborted the sequence, with a mixture of relief and reluctance. Of course, he already knew that the Master had hidden on Tersurus when his final regeneration had been used up. Some devastating force had ravaged his body and left him a crippled wreck.

But his TARDIS had left the world.

And that could only mean that Susan had been the one to trigger the Master's grotesque change. And that she had taken his TARDIS and gone on alone. There was no need for him to go to her aid, then. She had acted swiftly and certainly, and solved the last remaining problem.

So, the Master had already used up his last regeneration before he went to Tersurus. Susan had been the one to trigger the change into the decayed Pratt version, and then Goth meets up with the Pratt Master on Tersurus leading into The Deadly Assassin. So what happened on Tersurus is not a regeneration, but rather something that should have killed the Master, but instead just left him badly putrified.

Oh, and the Target novelisation of The Deadly Assassin actually says:

'And the Master's own death?'

Spandrell shrugged. 'You might almost say natural causes, sir. The body was extremely decayed. It's a wonder he stayed alive so long. Pne can only presume that he had come to the end of his regeneration cycle prematurely.'

Borusa frowned. 'I understand he was relatively young-not much older than the Doctor here.'

The Doctor was standing by the window, brooding over the lights of the Capitol City, far below, 'He was always a criminal, sir, throughout all his lives. Constant pressure, constant danger. Accelerated regenerations used as disguise... He was simply burnt out.'

...so the Master's burning through regenerations has nothing to do with what happened in Legacy of the Daleks. Delgado was already the 13th Master, because the Master had forced himself to regenerate into new incarnations as part of his schemes. Master of Spiders ☎  04:36, December 12, 2014 (UTC)