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- Like many early Doctor Who print stories, both comic and prose, the Doctor is referred to as "Doctor Who" or "Dr. Who". The word "doctor" is not even seen as a proper noun here when used on its own to refer to the character.
- This story can't seem to make up its mind about how to refer to the Doctor's time machine. Within the same paragraph, even, it calls it both "the Tardis" and simply "Tardis".
- As with other stories in the 1968 annual, the Second Doctor refers to Ben and Polly as "my children", or, individually, "my child", "my girl", or "my boy". Uncharacteristic of the Troughton Doctor, this seems to be a hold-over from the Hartnell interpretation; there was simply too little time between when Troughton took over and when this annual had to go to print for the annual's editors to understand Troughton's approach to the role.
- As in other illustrated stories throughout the annual, the Doctor is shown here wearing his stovepipe hat — another indicator of just how early this annual went to press.
- This story refers to the recent transformation from the First Doctor, calling the process both "rejuvenation" and "reincarnation" but not "regeneration".
- Polly is portrayed here as sensible and generally smarter than Ben. She's definitely the Doctor's "preferred" companion, hinted to stem from her unwavering faith in the Doctor in The Power of the Daleks.
- This story posits the notion that the TARDIS is a human invention, or, to quote, "the most complex and marvellous conveyance ever constructed by mankind".
- The Doctor's explanation to Ben of why they can't just leave a dangerous situation in the TARDIS boils down to the one the Tenth Doctor gives in The Girl in the Fireplace: they're part of events now, and if they just leave, the Arcturians might well successfully invade Earth.
- The Doctor says that he believes in destiny and fate, telling his companions that "if we just obey destiny blindly, all will be well". This is a significantly different view than the Doctor has otherwise taken. He flips to the completely opposite side of the fence by the time of The Waters of Mars.
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