The Doctor encounters the Terileptil, but his offer to take him off Earth is rejected.

Doctors at the clinic may encounter gaunt, malnourished mothers and deliver premature, underweight babies.

In addition, the Doctor has occasionally encountered himself in the form of his own incarnation, from the near future or past.

The Doctor has encountered the Face of Boe (as originally presented) three times.

Nyssa shows up, explaining that she was brought to Logopolis by the same figure that the Doctor encountered.

The story features the Doctor and his companions encountering an ancient civilisation of deactivated robots.

The curtains parted revealing the pastoral scene the Doctor had first encountered: the insectoids had disappeared.

He lacked any visible symptom of the radiation sickness that plagued virtually every soldier the Doctor had encountered.

The Doctor first encountered Sabbath in 1782.

Doctors encounter people who take up an undue amount of their time with trivial matters.