Dear Mr. Moffat,
As you may know, most of the fan base for Doctor Who would love to see the return of Classic Era companions, and with most of them getting up there in age you are swiftly running out of time with regards to the earlier actors from the series. I’ve seen a lot of talk on Facebook and other social media that would love to see Carol Ann Ford return as Susan, the Doctor’s granddaughter, and you’ve already set up an appearance for William Russel as Ian Chesterton by making him the headmaster of Coal Hill school.
Any and all past Companions would be great to see. I, myself, would love to see Frazer Hines & Wendy Padbury return as Jamie McCrimmon & Zoe Heriot.
In the Case of the 3rd Doctor’s companions, sadly only 3 still live: Katy Manning, Richard Franklin, and John Levene…despite having only these three left, an appearance by Jo Grant, Mike Yates, or Benton would still be great. Sadly with the passing of Nicholas Courtney & Elisabeth Sladen, the Brigadier & Sarah Jane are forever lost to any new appearances on the series, but I could see you having a guest appearance by Tommy Knight as Luke Smith telling the Doctor of the passing of Sarah Jane. And, of course, I loved the Cyber-Brigadier appearance in “Death in Heaven.”
With these suggestions and all the past companions that are still living, any would be a welcome nod to the past.
With much appreciation for you vision and dedication to Doctor Who,
The Second Geekhood Squad