This story debuted with either the Second or Third Doctor, then was reprinted with the Fourth Doctor. It may have had different companions in the reprint, as well. From an in-universe point of view, it's unclear which Doctor lived through these events.
a real world point of view
|Main enemy:||The Zirconians|
|Main setting:||Earth, 1974|
|Printed in:||Doctor Who Holiday Special 1974|
|Secret of the Tower||Perils of Paris|
The Doctor and new friend Sarah Jane Smith arrive on Earth to find the planet facing its greatest threat. Can the Doctor save Earth from a deadly virus? Just what are the creatures declaring genocide upon humanity?
to be added
- For the Mighty Midget Doctor Who Comic Fourth Doctor reprint, Sarah was given what was no doubt considered to be the new and dynamic name of Joan Brown, while the Brigadier had his moustache removed and glasses added – transforming him into General Maxwell-Lennon.
- As TV Comic's depiction of Sarah was so unlike that of Elisabeth Sladen, no alteration to the artwork was necessary in this case. However, the Doctor does still refer to 'Joan' as 'Sarah' in one panel that was presumably overlooked in the updating process.
to be added