DOCTOR WHO IN DETAIL

After Martha leaves the Doctor, the TARDIS dematerialises, and runs into a disturbance in space. Whilst the Doctor tries to stabilise the TARDIS he nearly bumps into someone else at the console. They both politely excuse themselves and continue at the console.

Until each realises the other should not be there. The tenth Doctor immediately recognises the newcomer, but the fifth Doctor has no idea who the tenth Doctor is. The tenth Doctor begins to remark about the fifth Doctor's appearance - a little baggier in the face, a few grey hairs, a jacket that no longer closes.

The fifth Doctor is worried about the state of his TARDIS and would prefer not to have a skinny idiot ranting in his face. The fifth Doctor wonders what has happened to the TARDIS configuration, still thinking he is in his TARDIS.

A level 5 alert sounds, and the fifth Doctor surmises that two TARDISes may have merged, even though there is only one TARDIS present. When the tenth Doctor tries to get the fifth Doctor to guess who he is, the fifth Doctor thinks he is a fan. The tenth Doctor reveals who he is, as the TARDIS's cloister bell starts to toll.

The tenth Doctor admits that it is his fault they have met. He was rebuilding the TARDIS and forgot to put the shields up, and the two TARDISes converged. The tenth Doctor is able to avert disaster by passing the TARDIS between a black hole and a super nova, each cancelling the other out.

The tenth Doctor reveals he didn't have to work out the solution - merely remember it from the fifth Doctor, who had watched the tenth Doctor perform the task. As the TARDISes separate the fifth Doctor begins to fade away. As he does, he reminds the tenth Doctor to put his shields up - just as the titanic breaks into the console room.