Roots: The Doctor quotes "With a Little Help From My Friends" Ian recalls the practice of driving sheep across minefields. Jurassic Park (see: Goofs)
Intertextuality: Ian's return to teaching after years of work in scientific research may be a reference to the intended casting of William Russell as an older Ian teaching at Brendan School in Mawdryn Undead.
Goofs: The Velociraptor that stalks the Doctor and Polly is regarded as quite a threat for a dinosaur known to be only the size of a small turkey, even in 1983 (Stephen Spielberg has a lot to answer for)
Dialogue Triumphs: "Waving a gun around never helps in my experience. It only makes people more willing to shoot you"
'You know I've always believed that you can't solve people's problems forever. All you can do is try to solve today's!'
The Doctor and Polly: "I still remember you facing up to the Cyberleader, demanding to know why he didn't care. What he said was logical, but what you said was right. You were an inspiration - I'm sorry I never told you that"
Continuity: The various companions and their adversaries have all aged since their last meeting with the Doctor. The Death Zone is varied, with different environments "lift one up, replace it with another". Its terrain includes bits of a solar probe and technology dating back to the early space faring races - Nyssa describes it as an artificially-created pocket dimension. Only a TARDIS can get around its barriers, but an anomaly has brought everyone here. The Doctor tells his former companions that, after returning from the Death Zone their memories of the experience may be hazy.
Dwarf star alloy is a super dense metal capable of absorbing a lot of energy. The alloy walls of the environment were constructed in zero gravity and can be disassembled at the flick of a switch in an emergency. A solar battery looks like a green box with a cheerful sun on its side.
The Daleks regard the Sontarans as a low grade threat because of their war, although for their part the Sontarans do not fear the Daleks either. The Sontarans say they know all the Doctor's incarnations, recognising the Fifth Doctor from records of their encounter with him on Samur (see; Links). Commander Skaal refers to the Sontaran invasion of Gallifrey (again, see Links). The Sontarans fought a rearguard action against the Daleks while battling the Rutans in the Madillon Cluster (see: Linx- sorry, Links) The Sontarans are in pod ships which can only travel through the environment's wider corridors (their ships are even bigger). They (or their travel pods) seem to have some shielding against Dalek fire. In their ranks are engineers. Their ships have tractor beams (an aspect Sara seems familiar with) Sontarans here are named Varsh, Skaal and Marshal Grex. They haven't yet mastered time corridor technology. Every Sontaran is issued with their own ship upon entering service; they are expected to maintain it at all times, replacing parts, performing upgrades and cleaning it daily.
Ian continued his research for another thirty years, and came out of retirement to take up teaching again. He is married to Barbara, who is writing a book. The Doctor tells him that he had intended to visit him several months earlier. Ian has noticeably aged in this story, contrary to the anecdote told by Sarah Jane in The Death of the Doctor [perhaps "they haven't aged" is more a turn of phrase rather than a literal description?]
Steven defended his world (presumably that of the Savages) from Sontarans when one of their probes crashed there "a few years ago." Consequently, he knows of their weak spot in their probic vent. His adopted home where he still leads has found peace "...more or less." He recalls Sara's death on Kembel.
Polly is married to Ben, and thinks that no-one believed that they would last as a couple and that her mother had a fit when she first brought Ben home to meet her parents. She believes that that making coffee was usually her main contribution to her adventures with the Doctor. She went barefoot at the Isle of Wight festival and was 'scooped' whilst on her way to a restaurant. She has size six feet and recalls the Doctor's change (though not as a regeneration)
Nyssa's comment that the Doctor hasn't visited her since they parted company suggests that this story takes place for her between Terminus and Cobwebs. Nyssa seems to be adept at sexing dinosaurs and affects a sonic weapon with the components of a ground radar.
The Doctor has the Master's teleport device and a bottle of Tabasco sauce in his pocket. Thes is the first reunion of the Doctor with this set of companions since their departures (see Box-Out). He tells Polly that he avoided calling himself a Time Lord while she was travelling with him as he was on the run from his people. He mentions Susan to Ian, but has never mentioned her to Nyssa.
Location: The Death Zone, Gallifrey, during the events of The Five Doctors.
Links: The Five Doctors. Ian mentions Barbara and Susan The Daleks (Ian's tactics) and The Chase. The Daleks' Master Plan, The Savages, The Faceless Ones, Terminus, The Two Doctors. The Doctor recalls Polly challenging the Cyber-Leader in Snowcap Base (The Tenth Planet) and taking down a guard duty of Cybermen (The Moonbase) His previous incarnation is described as "All teeth and curls" and he says "Brave heart, Polly." Polly's coffee-making anecdote references both The Tenth Planet and The Moonbase as well as the Companion Chronicle The Selachian Gambit. The Doctor's suggestion of his former companions' hazy memories post-Death Zone may be a nod to Sarah Jane's failure to recall the events of The Five Doctors during her meeting with the Doctor in School Reunion.
The Bottom Line: "'Sometimes it's too easy to keep on going forward. Perhaps sometimes I should give myself the luxury of looking back to appreciate all the good people I've left behind."
Eddie Robson takes a rather hairy premise (a Five Doctors cutaway, essentially) and turns it into a quick-turned adventure with a pretty decent set of pauses for each of the five companions of the Doctor, and a meditation on what it is to be his friend. It's some cast to juggle once you add the Daleks and Sontarans, but there are some lovely scenes, particularly for Steven and Ian, and the Doctor's rallying speech to Polly is a moving and affirming tribute to the greatest aspect of the Doctor's earliest companions - unashamed, modest normality. A rickety set, held together by devotion and fun - but isn't that where it all began?
THE RESURRECTION OF SARA KINGDOM
Sara Kingdom dies on Kembel at the end of The Daleks' Masterplan. This much is established Who lore. On the other hand, the Companion Chronicles devised a way of bringing Sara back to life in a manner of speaking, in a trilogy of stories featuring Sara, Steven and the Doctor. In Home Truths Sara's mind is duplicated by a sentient house on the world of Ely, and her duplicated consciousness lives on as the House relating other tales (The Drowned World, Guardian of the Solar System) until she is 'released' by a visiting academic who swaps places with her, the House restoring Sara's body (still in uniform) as it was when she first entered. Summoning the TARDIS to the House, the academic, 'Robert', offers a repentant Sara the chance of a new life, freedom from Ely, and possibly the chance to rave again with the Doctor. It is not known whether she took the opportunity.
The Sara time scooped in The Five Companions is, presumably, the resurrected Sara. She remembers her death (or at least is aware of it - perhaps the House granted these to her?), although the Fifth Doctor seems surprised to see her. We might infer from this that if Sara did re-enter the TARDIS post-Ely, then she was rescued by a future incarnation of the Doctor and scooped from a point in his future timeline - an unorthodox and unprecedented scenario for an incumbent Time Lord. The alternative, that his Sara is the 'real' Sara taken during her adventures with the Doctor, seems a little harder to fit in because of her dialogue with Steven, as well as the apparent age of the character (all companions having reasonably aged in this story.)